| Message ID | 1498484330-10840-2-git-send-email-thunder.leizhen@huawei.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | arm-smmu: performance optimization | expand |
Hi Zhen Lei, Nate (CC'd), Robin and I have been working on something very similar to this series, but this patch is different to what we had planned. More below. On Mon, Jun 26, 2017 at 09:38:46PM +0800, Zhen Lei wrote: > Because all TLBI commands should be followed by a SYNC command, to make > sure that it has been completely finished. So we can just add the TLBI > commands into the queue, and put off the execution until meet SYNC or > other commands. To prevent the followed SYNC command waiting for a long > time because of too many commands have been delayed, restrict the max > delayed number. > > According to my test, I got the same performance data as I replaced writel > with writel_relaxed in queue_inc_prod. > > Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> > --- > drivers/iommu/arm-smmu-v3.c | 42 +++++++++++++++++++++++++++++++++++++----- > 1 file changed, 37 insertions(+), 5 deletions(-) > > diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c > index 291da5f..4481123 100644 > --- a/drivers/iommu/arm-smmu-v3.c > +++ b/drivers/iommu/arm-smmu-v3.c > @@ -337,6 +337,7 @@ > /* Command queue */ > #define CMDQ_ENT_DWORDS 2 > #define CMDQ_MAX_SZ_SHIFT 8 > +#define CMDQ_MAX_DELAYED 32 > > #define CMDQ_ERR_SHIFT 24 > #define CMDQ_ERR_MASK 0x7f > @@ -472,6 +473,7 @@ struct arm_smmu_cmdq_ent { > }; > } cfgi; > > + #define CMDQ_OP_TLBI_NH_ALL 0x10 > #define CMDQ_OP_TLBI_NH_ASID 0x11 > #define CMDQ_OP_TLBI_NH_VA 0x12 > #define CMDQ_OP_TLBI_EL2_ALL 0x20 > @@ -499,6 +501,7 @@ struct arm_smmu_cmdq_ent { > > struct arm_smmu_queue { > int irq; /* Wired interrupt */ > + u32 nr_delay; > > __le64 *base; > dma_addr_t base_dma; > @@ -722,11 +725,16 @@ static int queue_sync_prod(struct arm_smmu_queue *q) > return ret; > } > > -static void queue_inc_prod(struct arm_smmu_queue *q) > +static void queue_inc_swprod(struct arm_smmu_queue *q) > { > - u32 prod = (Q_WRP(q, q->prod) | Q_IDX(q, q->prod)) + 1; > + u32 prod = q->prod + 1; > > q->prod = Q_OVF(q, q->prod) | Q_WRP(q, prod) | Q_IDX(q, prod); > +} > + > +static void queue_inc_prod(struct arm_smmu_queue *q) > +{ > + queue_inc_swprod(q); > writel(q->prod, q->prod_reg); > } > > @@ -761,13 +769,24 @@ static void queue_write(__le64 *dst, u64 *src, size_t n_dwords) > *dst++ = cpu_to_le64(*src++); > } > > -static int queue_insert_raw(struct arm_smmu_queue *q, u64 *ent) > +static int queue_insert_raw(struct arm_smmu_queue *q, u64 *ent, int optimize) > { > if (queue_full(q)) > return -ENOSPC; > > queue_write(Q_ENT(q, q->prod), ent, q->ent_dwords); > - queue_inc_prod(q); > + > + /* > + * We don't want too many commands to be delayed, this may lead the > + * followed sync command to wait for a long time. > + */ > + if (optimize && (++q->nr_delay < CMDQ_MAX_DELAYED)) { > + queue_inc_swprod(q); > + } else { > + queue_inc_prod(q); > + q->nr_delay = 0; > + } > + So here, you're effectively putting invalidation commands into the command queue without updating PROD. Do you actually see a performance advantage from doing so? Another side of the argument would be that we should be moving PROD as soon as we can, so that the SMMU can process invalidation commands in the background and reduce the cost of the final SYNC operation when the high-level unmap operation is complete. Will
On 2017/6/28 17:32, Will Deacon wrote: > Hi Zhen Lei, > > Nate (CC'd), Robin and I have been working on something very similar to > this series, but this patch is different to what we had planned. More below. > > On Mon, Jun 26, 2017 at 09:38:46PM +0800, Zhen Lei wrote: >> Because all TLBI commands should be followed by a SYNC command, to make >> sure that it has been completely finished. So we can just add the TLBI >> commands into the queue, and put off the execution until meet SYNC or >> other commands. To prevent the followed SYNC command waiting for a long >> time because of too many commands have been delayed, restrict the max >> delayed number. >> >> According to my test, I got the same performance data as I replaced writel >> with writel_relaxed in queue_inc_prod. >> >> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> >> --- >> drivers/iommu/arm-smmu-v3.c | 42 +++++++++++++++++++++++++++++++++++++----- >> 1 file changed, 37 insertions(+), 5 deletions(-) >> >> diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c >> index 291da5f..4481123 100644 >> --- a/drivers/iommu/arm-smmu-v3.c >> +++ b/drivers/iommu/arm-smmu-v3.c >> @@ -337,6 +337,7 @@ >> /* Command queue */ >> #define CMDQ_ENT_DWORDS 2 >> #define CMDQ_MAX_SZ_SHIFT 8 >> +#define CMDQ_MAX_DELAYED 32 >> >> #define CMDQ_ERR_SHIFT 24 >> #define CMDQ_ERR_MASK 0x7f >> @@ -472,6 +473,7 @@ struct arm_smmu_cmdq_ent { >> }; >> } cfgi; >> >> + #define CMDQ_OP_TLBI_NH_ALL 0x10 >> #define CMDQ_OP_TLBI_NH_ASID 0x11 >> #define CMDQ_OP_TLBI_NH_VA 0x12 >> #define CMDQ_OP_TLBI_EL2_ALL 0x20 >> @@ -499,6 +501,7 @@ struct arm_smmu_cmdq_ent { >> >> struct arm_smmu_queue { >> int irq; /* Wired interrupt */ >> + u32 nr_delay; >> >> __le64 *base; >> dma_addr_t base_dma; >> @@ -722,11 +725,16 @@ static int queue_sync_prod(struct arm_smmu_queue *q) >> return ret; >> } >> >> -static void queue_inc_prod(struct arm_smmu_queue *q) >> +static void queue_inc_swprod(struct arm_smmu_queue *q) >> { >> - u32 prod = (Q_WRP(q, q->prod) | Q_IDX(q, q->prod)) + 1; >> + u32 prod = q->prod + 1; >> >> q->prod = Q_OVF(q, q->prod) | Q_WRP(q, prod) | Q_IDX(q, prod); >> +} >> + >> +static void queue_inc_prod(struct arm_smmu_queue *q) >> +{ >> + queue_inc_swprod(q); >> writel(q->prod, q->prod_reg); >> } >> >> @@ -761,13 +769,24 @@ static void queue_write(__le64 *dst, u64 *src, size_t n_dwords) >> *dst++ = cpu_to_le64(*src++); >> } >> >> -static int queue_insert_raw(struct arm_smmu_queue *q, u64 *ent) >> +static int queue_insert_raw(struct arm_smmu_queue *q, u64 *ent, int optimize) >> { >> if (queue_full(q)) >> return -ENOSPC; >> >> queue_write(Q_ENT(q, q->prod), ent, q->ent_dwords); >> - queue_inc_prod(q); >> + >> + /* >> + * We don't want too many commands to be delayed, this may lead the >> + * followed sync command to wait for a long time. >> + */ >> + if (optimize && (++q->nr_delay < CMDQ_MAX_DELAYED)) { >> + queue_inc_swprod(q); >> + } else { >> + queue_inc_prod(q); >> + q->nr_delay = 0; >> + } >> + > > So here, you're effectively putting invalidation commands into the command > queue without updating PROD. Do you actually see a performance advantage > from doing so? Another side of the argument would be that we should be Yes, my sas ssd performance test showed that it can improve about 100-150K/s(the same to I directly replace writel with writel_relaxed). And the average execution time of iommu_unmap(which called by iommu_dma_unmap_sg) dropped from 10us to 5us. > moving PROD as soon as we can, so that the SMMU can process invalidation > commands in the background and reduce the cost of the final SYNC operation > when the high-level unmap operation is complete. There maybe that __iowmb() is more expensive than wait for tlbi complete. Except the time of __iowmb() itself, it also protected by spinlock, lock confliction will rise rapidly in the stress scene. __iowmb() average cost 300-500ns(Sorry, I forget the exact value). In addition, after applied this patcheset and Robin's v2, and my earlier dma64 iova optimization patchset. Our net performance test got the same data to global bypass. But sas ssd still have more than 20% dropped. Maybe we should still focus at map/unamp, because the average execution time of iova alloc/free is only about 400ns. By the way, patch2-5 is more effective than this one, it can improve more than 350K/s. And with it, we can got about 100-150K/s improvement of Robin's v2. Otherwise, I saw non effective of Robin's v2. Sorry, I have not tested how about this patch without patch2-5. Further more, I got the same performance data to global bypass for the traditional mechanical hard disk with only patch2-5(without this patch and Robin's). > > Will > > . > -- Thanks! BestRegards
+ On 29/06/2017 03:08, Leizhen (ThunderTown) wrote: > > > On 2017/6/28 17:32, Will Deacon wrote: >> Hi Zhen Lei, >> >> Nate (CC'd), Robin and I have been working on something very similar to >> this series, but this patch is different to what we had planned. More below. >> >> On Mon, Jun 26, 2017 at 09:38:46PM +0800, Zhen Lei wrote: >>> Because all TLBI commands should be followed by a SYNC command, to make >>> sure that it has been completely finished. So we can just add the TLBI >>> commands into the queue, and put off the execution until meet SYNC or >>> other commands. To prevent the followed SYNC command waiting for a long >>> time because of too many commands have been delayed, restrict the max >>> delayed number. >>> >>> According to my test, I got the same performance data as I replaced writel >>> with writel_relaxed in queue_inc_prod. >>> >>> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> >>> --- >>> drivers/iommu/arm-smmu-v3.c | 42 +++++++++++++++++++++++++++++++++++++----- >>> 1 file changed, 37 insertions(+), 5 deletions(-) >>> >>> diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c >>> index 291da5f..4481123 100644 >>> --- a/drivers/iommu/arm-smmu-v3.c >>> +++ b/drivers/iommu/arm-smmu-v3.c >>> @@ -337,6 +337,7 @@ >>> /* Command queue */ >>> #define CMDQ_ENT_DWORDS 2 >>> #define CMDQ_MAX_SZ_SHIFT 8 >>> +#define CMDQ_MAX_DELAYED 32 >>> >>> #define CMDQ_ERR_SHIFT 24 >>> #define CMDQ_ERR_MASK 0x7f >>> @@ -472,6 +473,7 @@ struct arm_smmu_cmdq_ent { >>> }; >>> } cfgi; >>> >>> + #define CMDQ_OP_TLBI_NH_ALL 0x10 >>> #define CMDQ_OP_TLBI_NH_ASID 0x11 >>> #define CMDQ_OP_TLBI_NH_VA 0x12 >>> #define CMDQ_OP_TLBI_EL2_ALL 0x20 >>> @@ -499,6 +501,7 @@ struct arm_smmu_cmdq_ent { >>> >>> struct arm_smmu_queue { >>> int irq; /* Wired interrupt */ >>> + u32 nr_delay; >>> >>> __le64 *base; >>> dma_addr_t base_dma; >>> @@ -722,11 +725,16 @@ static int queue_sync_prod(struct arm_smmu_queue *q) >>> return ret; >>> } >>> >>> -static void queue_inc_prod(struct arm_smmu_queue *q) >>> +static void queue_inc_swprod(struct arm_smmu_queue *q) >>> { >>> - u32 prod = (Q_WRP(q, q->prod) | Q_IDX(q, q->prod)) + 1; >>> + u32 prod = q->prod + 1; >>> >>> q->prod = Q_OVF(q, q->prod) | Q_WRP(q, prod) | Q_IDX(q, prod); >>> +} >>> + >>> +static void queue_inc_prod(struct arm_smmu_queue *q) >>> +{ >>> + queue_inc_swprod(q); >>> writel(q->prod, q->prod_reg); >>> } >>> >>> @@ -761,13 +769,24 @@ static void queue_write(__le64 *dst, u64 *src, size_t n_dwords) >>> *dst++ = cpu_to_le64(*src++); >>> } >>> >>> -static int queue_insert_raw(struct arm_smmu_queue *q, u64 *ent) >>> +static int queue_insert_raw(struct arm_smmu_queue *q, u64 *ent, int optimize) >>> { >>> if (queue_full(q)) >>> return -ENOSPC; >>> >>> queue_write(Q_ENT(q, q->prod), ent, q->ent_dwords); >>> - queue_inc_prod(q); >>> + >>> + /* >>> + * We don't want too many commands to be delayed, this may lead the >>> + * followed sync command to wait for a long time. >>> + */ >>> + if (optimize && (++q->nr_delay < CMDQ_MAX_DELAYED)) { >>> + queue_inc_swprod(q); >>> + } else { >>> + queue_inc_prod(q); >>> + q->nr_delay = 0; >>> + } >>> + >> >> So here, you're effectively putting invalidation commands into the command >> queue without updating PROD. Do you actually see a performance advantage >> from doing so? Another side of the argument would be that we should be > Yes, my sas ssd performance test showed that it can improve about 100-150K/s(the same to I directly replace > writel with writel_relaxed). And the average execution time of iommu_unmap(which called by iommu_dma_unmap_sg) > dropped from 10us to 5us. > >> moving PROD as soon as we can, so that the SMMU can process invalidation >> commands in the background and reduce the cost of the final SYNC operation >> when the high-level unmap operation is complete. > There maybe that __iowmb() is more expensive than wait for tlbi complete. Except the time of __iowmb() > itself, it also protected by spinlock, lock confliction will rise rapidly in the stress scene. __iowmb() > average cost 300-500ns(Sorry, I forget the exact value). > > In addition, after applied this patcheset and Robin's v2, and my earlier dma64 iova optimization patchset. > Our net performance test got the same data to global bypass. But sas ssd still have more than 20% dropped. > Maybe we should still focus at map/unamp, because the average execution time of iova alloc/free is only > about 400ns. > > By the way, patch2-5 is more effective than this one, it can improve more than 350K/s. And with it, we can > got about 100-150K/s improvement of Robin's v2. Otherwise, I saw non effective of Robin's v2. Sorry, I have > not tested how about this patch without patch2-5. Further more, I got the same performance data to global > bypass for the traditional mechanical hard disk with only patch2-5(without this patch and Robin's). > >> >> Will >> >> . >> >
On Mon, 17 Jul 2017 14:06:42 +0100 John Garry <john.garry@huawei.com> wrote: > + > > On 29/06/2017 03:08, Leizhen (ThunderTown) wrote: > > > > > > On 2017/6/28 17:32, Will Deacon wrote: > >> Hi Zhen Lei, > >> > >> Nate (CC'd), Robin and I have been working on something very similar to > >> this series, but this patch is different to what we had planned. More below. > >> > >> On Mon, Jun 26, 2017 at 09:38:46PM +0800, Zhen Lei wrote: > >>> Because all TLBI commands should be followed by a SYNC command, to make > >>> sure that it has been completely finished. So we can just add the TLBI > >>> commands into the queue, and put off the execution until meet SYNC or > >>> other commands. To prevent the followed SYNC command waiting for a long > >>> time because of too many commands have been delayed, restrict the max > >>> delayed number. > >>> > >>> According to my test, I got the same performance data as I replaced writel > >>> with writel_relaxed in queue_inc_prod. > >>> > >>> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> > >>> --- > >>> drivers/iommu/arm-smmu-v3.c | 42 +++++++++++++++++++++++++++++++++++++----- > >>> 1 file changed, 37 insertions(+), 5 deletions(-) > >>> > >>> diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c > >>> index 291da5f..4481123 100644 > >>> --- a/drivers/iommu/arm-smmu-v3.c > >>> +++ b/drivers/iommu/arm-smmu-v3.c > >>> @@ -337,6 +337,7 @@ > >>> /* Command queue */ > >>> #define CMDQ_ENT_DWORDS 2 > >>> #define CMDQ_MAX_SZ_SHIFT 8 > >>> +#define CMDQ_MAX_DELAYED 32 > >>> > >>> #define CMDQ_ERR_SHIFT 24 > >>> #define CMDQ_ERR_MASK 0x7f > >>> @@ -472,6 +473,7 @@ struct arm_smmu_cmdq_ent { > >>> }; > >>> } cfgi; > >>> > >>> + #define CMDQ_OP_TLBI_NH_ALL 0x10 > >>> #define CMDQ_OP_TLBI_NH_ASID 0x11 > >>> #define CMDQ_OP_TLBI_NH_VA 0x12 > >>> #define CMDQ_OP_TLBI_EL2_ALL 0x20 > >>> @@ -499,6 +501,7 @@ struct arm_smmu_cmdq_ent { > >>> > >>> struct arm_smmu_queue { > >>> int irq; /* Wired interrupt */ > >>> + u32 nr_delay; > >>> > >>> __le64 *base; > >>> dma_addr_t base_dma; > >>> @@ -722,11 +725,16 @@ static int queue_sync_prod(struct arm_smmu_queue *q) > >>> return ret; > >>> } > >>> > >>> -static void queue_inc_prod(struct arm_smmu_queue *q) > >>> +static void queue_inc_swprod(struct arm_smmu_queue *q) > >>> { > >>> - u32 prod = (Q_WRP(q, q->prod) | Q_IDX(q, q->prod)) + 1; > >>> + u32 prod = q->prod + 1; > >>> > >>> q->prod = Q_OVF(q, q->prod) | Q_WRP(q, prod) | Q_IDX(q, prod); > >>> +} > >>> + > >>> +static void queue_inc_prod(struct arm_smmu_queue *q) > >>> +{ > >>> + queue_inc_swprod(q); > >>> writel(q->prod, q->prod_reg); > >>> } > >>> > >>> @@ -761,13 +769,24 @@ static void queue_write(__le64 *dst, u64 *src, size_t n_dwords) > >>> *dst++ = cpu_to_le64(*src++); > >>> } > >>> > >>> -static int queue_insert_raw(struct arm_smmu_queue *q, u64 *ent) > >>> +static int queue_insert_raw(struct arm_smmu_queue *q, u64 *ent, int optimize) > >>> { > >>> if (queue_full(q)) > >>> return -ENOSPC; > >>> > >>> queue_write(Q_ENT(q, q->prod), ent, q->ent_dwords); > >>> - queue_inc_prod(q); > >>> + > >>> + /* > >>> + * We don't want too many commands to be delayed, this may lead the > >>> + * followed sync command to wait for a long time. > >>> + */ > >>> + if (optimize && (++q->nr_delay < CMDQ_MAX_DELAYED)) { > >>> + queue_inc_swprod(q); > >>> + } else { > >>> + queue_inc_prod(q); > >>> + q->nr_delay = 0; > >>> + } > >>> + > >> > >> So here, you're effectively putting invalidation commands into the command > >> queue without updating PROD. Do you actually see a performance advantage > >> from doing so? Another side of the argument would be that we should be > > Yes, my sas ssd performance test showed that it can improve about 100-150K/s(the same to I directly replace > > writel with writel_relaxed). And the average execution time of iommu_unmap(which called by iommu_dma_unmap_sg) > > dropped from 10us to 5us. > > > >> moving PROD as soon as we can, so that the SMMU can process invalidation > >> commands in the background and reduce the cost of the final SYNC operation > >> when the high-level unmap operation is complete. > > There maybe that __iowmb() is more expensive than wait for tlbi complete. Except the time of __iowmb() > > itself, it also protected by spinlock, lock confliction will rise rapidly in the stress scene. __iowmb() > > average cost 300-500ns(Sorry, I forget the exact value). > > > > In addition, after applied this patcheset and Robin's v2, and my earlier dma64 iova optimization patchset. > > Our net performance test got the same data to global bypass. But sas ssd still have more than 20% dropped. > > Maybe we should still focus at map/unamp, because the average execution time of iova alloc/free is only > > about 400ns. > > > > By the way, patch2-5 is more effective than this one, it can improve more than 350K/s. And with it, we can > > got about 100-150K/s improvement of Robin's v2. Otherwise, I saw non effective of Robin's v2. Sorry, I have > > not tested how about this patch without patch2-5. Further more, I got the same performance data to global > > bypass for the traditional mechanical hard disk with only patch2-5(without this patch and Robin's). > > Hi All, I'm a bit of late entry to this discussion. Just been running some more detailed tests on our d05 boards and wanted to bring some more numbers to the discussion. All tests against 4.12 with the following additions: * Robin's series removing the io-pgtable spinlock (and a few recent fixes) * Cherry picked updates to the sas driver, merged prior to 4.13-rc1 * An additional HNS (network card) bug fix that will be upstreamed shortly. I've broken the results down into this patch and this patch + the remainder of the set. As leizhen mentioned we got a nice little performance bump from Robin's series so that was applied first (as it's in mainline now) SAS tests were fio with noop scheduler, 4k block size and various io depths 1 process per disk. Note this is probably a different setup to leizhen's original numbers. Precentages are off the performance seen with the smmu disabled. SAS 4.12 - none of this series. SMMU disabled read io-depth 32 - 384K IOPS (100%) read io-depth 2048 - 950K IOPS (100%) rw io-depth 32 - 166K IOPS (100%) rw io-depth 2048 - 340K IOPS (100%) SMMU enabled read io-depth 32 - 201K IOPS (52%) read io-depth 2048 - 306K IOPS (32%) rw io-depth 32 - 99K IOPS (60%) rw io-depth 2048 - 150K IOPS (44%) Robin's recent series with fixes as seen on list (now merged) SMMU enabled. read io-depth 32 - 208K IOPS (54%) read io-depth 2048 - 335K IOPS (35%) rw io-depth 32 - 105K IOPS (63%) rw io-depth 2048 - 165K IOPS (49%) 4.12 + Robin's series + just this patch SMMU enabled (iommu/arm-smmu-v3: put of the execution of TLBI* to reduce lock conflict) read io-depth 32 - 225K IOPS (59%) read io-depth 2048 - 365K IOPS (38%) rw io-depth 32 - 110K IOPS (66%) rw io-depth 2048 - 179K IOPS (53%) 4.12 + Robin's series + Second part of this series (iommu/arm-smmu-v3: put of the execution of TLBI* to reduce lock conflict) (iommu: add a new member unmap_tlb_sync into struct iommu_ops) (iommu/arm-smmu-v3: add supprot for unmap an iova range with only on tlb sync) (iommu/arm-smmu: add support for unmap of a memory range with only one tlb sync) read io-depth 32 - 225K IOPS (59%) read io-depth 2048 - 833K IOPS (88%) rw io-depth 32 - 112K IOPS (67%) rw io-depth 2048 - 220K IOPS (65%) Robin's series gave us small gains across the board (3-5% recovered) relative to the no smmu performance (which we are taking as the ideal case) This first patch gets us back another 2-5% of the no smmu performance The next few patches get us very little advantage on the small io-depths but make a large difference to the larger io-depths - in particular the read IOPS which is over twice as fast as without the series. For HNS it seems that we are less dependent on the SMMU performance and can reach the non SMMU speed. Tests with iperf -t 30 -i 10 -c IPADDRESS -P 3 last 10 seconds taken to avoid any initial variability. The server end of the link was always running with smmu v3 disabled so as to act as a fast sink of the data. Some variation seen across repeat runs. Mainline v4.12 + network card fix NO SMMU 9.42 GBits/sec SMMU 4.36 GBits/sec (46%) Robin's io-pgtable spinlock series 6.68 to 7.34 (71% - 78% variation across runs) Just this patch SMMU enabled (iommu/arm-smmu-v3: put of the execution of TLBI* to reduce lock conflict) 7.96-8.8 GBits/sec (85% - 94% some variation across runs) Full series (iommu/arm-smmu-v3: put of the execution of TLBI* to reduce lock conflict) (iommu: add a new member unmap_tlb_sync into struct iommu_ops) (iommu/arm-smmu-v3: add supprot for unmap an iova range with only on tlb sync) (iommu/arm-smmu: add support for unmap of a memory range with only one tlb sync) 9.42 GBits/Sec (100%) So HNS test shows a greater boost from Robin's series and this first patch. This is most likely because the HNS test is not putting as high a load on the SMMU and associated code as the SAS test. In both cases however, this shows that both parts of this patch series are beneficial. So on to the questions ;) Will, you mentioned that along with Robin and Nate you were working on a somewhat related strategy to improve the performance. Any ETA on that? As you might imagine, with the above numbers we are very keen to try and move forward with this as quickly as possible. If you want additional testing we would be happy to help. Thanks, Jonathan > >> > >> Will > >> > >> . > >> > > > >
Hi Jonathan, On 7/17/2017 10:23 AM, Jonathan Cameron wrote: > On Mon, 17 Jul 2017 14:06:42 +0100 > John Garry <john.garry@huawei.com> wrote: > >> + >> >> On 29/06/2017 03:08, Leizhen (ThunderTown) wrote: >>> >>> >>> On 2017/6/28 17:32, Will Deacon wrote: >>>> Hi Zhen Lei, >>>> >>>> Nate (CC'd), Robin and I have been working on something very similar to >>>> this series, but this patch is different to what we had planned. More below. >>>> >>>> On Mon, Jun 26, 2017 at 09:38:46PM +0800, Zhen Lei wrote: >>>>> Because all TLBI commands should be followed by a SYNC command, to make >>>>> sure that it has been completely finished. So we can just add the TLBI >>>>> commands into the queue, and put off the execution until meet SYNC or >>>>> other commands. To prevent the followed SYNC command waiting for a long >>>>> time because of too many commands have been delayed, restrict the max >>>>> delayed number. >>>>> >>>>> According to my test, I got the same performance data as I replaced writel >>>>> with writel_relaxed in queue_inc_prod. >>>>> >>>>> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> >>>>> --- >>>>> drivers/iommu/arm-smmu-v3.c | 42 +++++++++++++++++++++++++++++++++++++----- >>>>> 1 file changed, 37 insertions(+), 5 deletions(-) >>>>> >>>>> diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c >>>>> index 291da5f..4481123 100644 >>>>> --- a/drivers/iommu/arm-smmu-v3.c >>>>> +++ b/drivers/iommu/arm-smmu-v3.c >>>>> @@ -337,6 +337,7 @@ >>>>> /* Command queue */ >>>>> #define CMDQ_ENT_DWORDS 2 >>>>> #define CMDQ_MAX_SZ_SHIFT 8 >>>>> +#define CMDQ_MAX_DELAYED 32 >>>>> >>>>> #define CMDQ_ERR_SHIFT 24 >>>>> #define CMDQ_ERR_MASK 0x7f >>>>> @@ -472,6 +473,7 @@ struct arm_smmu_cmdq_ent { >>>>> }; >>>>> } cfgi; >>>>> >>>>> + #define CMDQ_OP_TLBI_NH_ALL 0x10 >>>>> #define CMDQ_OP_TLBI_NH_ASID 0x11 >>>>> #define CMDQ_OP_TLBI_NH_VA 0x12 >>>>> #define CMDQ_OP_TLBI_EL2_ALL 0x20 >>>>> @@ -499,6 +501,7 @@ struct arm_smmu_cmdq_ent { >>>>> >>>>> struct arm_smmu_queue { >>>>> int irq; /* Wired interrupt */ >>>>> + u32 nr_delay; >>>>> >>>>> __le64 *base; >>>>> dma_addr_t base_dma; >>>>> @@ -722,11 +725,16 @@ static int queue_sync_prod(struct arm_smmu_queue *q) >>>>> return ret; >>>>> } >>>>> >>>>> -static void queue_inc_prod(struct arm_smmu_queue *q) >>>>> +static void queue_inc_swprod(struct arm_smmu_queue *q) >>>>> { >>>>> - u32 prod = (Q_WRP(q, q->prod) | Q_IDX(q, q->prod)) + 1; >>>>> + u32 prod = q->prod + 1; >>>>> >>>>> q->prod = Q_OVF(q, q->prod) | Q_WRP(q, prod) | Q_IDX(q, prod); >>>>> +} >>>>> + >>>>> +static void queue_inc_prod(struct arm_smmu_queue *q) >>>>> +{ >>>>> + queue_inc_swprod(q); >>>>> writel(q->prod, q->prod_reg); >>>>> } >>>>> >>>>> @@ -761,13 +769,24 @@ static void queue_write(__le64 *dst, u64 *src, size_t n_dwords) >>>>> *dst++ = cpu_to_le64(*src++); >>>>> } >>>>> >>>>> -static int queue_insert_raw(struct arm_smmu_queue *q, u64 *ent) >>>>> +static int queue_insert_raw(struct arm_smmu_queue *q, u64 *ent, int optimize) >>>>> { >>>>> if (queue_full(q)) >>>>> return -ENOSPC; >>>>> >>>>> queue_write(Q_ENT(q, q->prod), ent, q->ent_dwords); >>>>> - queue_inc_prod(q); >>>>> + >>>>> + /* >>>>> + * We don't want too many commands to be delayed, this may lead the >>>>> + * followed sync command to wait for a long time. >>>>> + */ >>>>> + if (optimize && (++q->nr_delay < CMDQ_MAX_DELAYED)) { >>>>> + queue_inc_swprod(q); >>>>> + } else { >>>>> + queue_inc_prod(q); >>>>> + q->nr_delay = 0; >>>>> + } >>>>> + >>>> >>>> So here, you're effectively putting invalidation commands into the command >>>> queue without updating PROD. Do you actually see a performance advantage >>>> from doing so? Another side of the argument would be that we should be >>> Yes, my sas ssd performance test showed that it can improve about 100-150K/s(the same to I directly replace >>> writel with writel_relaxed). And the average execution time of iommu_unmap(which called by iommu_dma_unmap_sg) >>> dropped from 10us to 5us. >>> >>>> moving PROD as soon as we can, so that the SMMU can process invalidation >>>> commands in the background and reduce the cost of the final SYNC operation >>>> when the high-level unmap operation is complete. >>> There maybe that __iowmb() is more expensive than wait for tlbi complete. Except the time of __iowmb() >>> itself, it also protected by spinlock, lock confliction will rise rapidly in the stress scene. __iowmb() >>> average cost 300-500ns(Sorry, I forget the exact value). >>> >>> In addition, after applied this patcheset and Robin's v2, and my earlier dma64 iova optimization patchset. >>> Our net performance test got the same data to global bypass. But sas ssd still have more than 20% dropped. >>> Maybe we should still focus at map/unamp, because the average execution time of iova alloc/free is only >>> about 400ns. >>> >>> By the way, patch2-5 is more effective than this one, it can improve more than 350K/s. And with it, we can >>> got about 100-150K/s improvement of Robin's v2. Otherwise, I saw non effective of Robin's v2. Sorry, I have >>> not tested how about this patch without patch2-5. Further more, I got the same performance data to global >>> bypass for the traditional mechanical hard disk with only patch2-5(without this patch and Robin's). >>> > Hi All, > > I'm a bit of late entry to this discussion. Just been running some more > detailed tests on our d05 boards and wanted to bring some more numbers to > the discussion. > > All tests against 4.12 with the following additions: > * Robin's series removing the io-pgtable spinlock (and a few recent fixes) > * Cherry picked updates to the sas driver, merged prior to 4.13-rc1 > * An additional HNS (network card) bug fix that will be upstreamed shortly. > > I've broken the results down into this patch and this patch + the remainder > of the set. As leizhen mentioned we got a nice little performance > bump from Robin's series so that was applied first (as it's in mainline now) > > SAS tests were fio with noop scheduler, 4k block size and various io depths > 1 process per disk. Note this is probably a different setup to leizhen's > original numbers. > > Precentages are off the performance seen with the smmu disabled. > SAS > 4.12 - none of this series. > SMMU disabled > read io-depth 32 - 384K IOPS (100%) > read io-depth 2048 - 950K IOPS (100%) > rw io-depth 32 - 166K IOPS (100%) > rw io-depth 2048 - 340K IOPS (100%) > > SMMU enabled > read io-depth 32 - 201K IOPS (52%) > read io-depth 2048 - 306K IOPS (32%) > rw io-depth 32 - 99K IOPS (60%) > rw io-depth 2048 - 150K IOPS (44%) > > Robin's recent series with fixes as seen on list (now merged) > SMMU enabled. > read io-depth 32 - 208K IOPS (54%) > read io-depth 2048 - 335K IOPS (35%) > rw io-depth 32 - 105K IOPS (63%) > rw io-depth 2048 - 165K IOPS (49%) > > 4.12 + Robin's series + just this patch SMMU enabled > > (iommu/arm-smmu-v3: put of the execution of TLBI* to reduce lock conflict) > > read io-depth 32 - 225K IOPS (59%) > read io-depth 2048 - 365K IOPS (38%) > rw io-depth 32 - 110K IOPS (66%) > rw io-depth 2048 - 179K IOPS (53%) > > 4.12 + Robin's series + Second part of this series > > (iommu/arm-smmu-v3: put of the execution of TLBI* to reduce lock conflict) > (iommu: add a new member unmap_tlb_sync into struct iommu_ops) > (iommu/arm-smmu-v3: add supprot for unmap an iova range with only on tlb sync) > (iommu/arm-smmu: add support for unmap of a memory range with only one tlb sync) > > read io-depth 32 - 225K IOPS (59%) > read io-depth 2048 - 833K IOPS (88%) > rw io-depth 32 - 112K IOPS (67%) > rw io-depth 2048 - 220K IOPS (65%) > > Robin's series gave us small gains across the board (3-5% recovered) > relative to the no smmu performance (which we are taking as the ideal case) > > This first patch gets us back another 2-5% of the no smmu performance > > The next few patches get us very little advantage on the small io-depths > but make a large difference to the larger io-depths - in particular the > read IOPS which is over twice as fast as without the series. > > For HNS it seems that we are less dependent on the SMMU performance and > can reach the non SMMU speed. > > Tests with > iperf -t 30 -i 10 -c IPADDRESS -P 3 last 10 seconds taken to avoid any > initial variability. > > The server end of the link was always running with smmu v3 disabled > so as to act as a fast sink of the data. Some variation seen across > repeat runs. > > Mainline v4.12 + network card fix > NO SMMU > 9.42 GBits/sec > > SMMU > 4.36 GBits/sec (46%) > > Robin's io-pgtable spinlock series > > 6.68 to 7.34 (71% - 78% variation across runs) > > Just this patch SMMU enabled > > (iommu/arm-smmu-v3: put of the execution of TLBI* to reduce lock conflict) > > 7.96-8.8 GBits/sec (85% - 94% some variation across runs) > > Full series > > (iommu/arm-smmu-v3: put of the execution of TLBI* to reduce lock conflict) > (iommu: add a new member unmap_tlb_sync into struct iommu_ops) > (iommu/arm-smmu-v3: add supprot for unmap an iova range with only on tlb sync) > (iommu/arm-smmu: add support for unmap of a memory range with only one tlb sync) > > 9.42 GBits/Sec (100%) > > So HNS test shows a greater boost from Robin's series and this first patch. > This is most likely because the HNS test is not putting as high a load on > the SMMU and associated code as the SAS test. > > In both cases however, this shows that both parts of this patch > series are beneficial. > > So on to the questions ;) > > Will, you mentioned that along with Robin and Nate you were working on > a somewhat related strategy to improve the performance. Any ETA on that? The strategy I was working on is basically equivalent to the second part of the series. I will test your patches out sometime this week, and I'll also try to have our performance team run it through their whole suite. > > As you might imagine, with the above numbers we are very keen to try and > move forward with this as quickly as possible. > > If you want additional testing we would be happy to help. > > Thanks, > > Jonathan > > > >>>> >>>> Will >>>> >>>> . >>>> >>> >> >> > > -- Qualcomm Datacenter Technologies as an affiliate of Qualcomm Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.
On Mon, 17 Jul 2017 13:28:47 -0400 Nate Watterson <nwatters@codeaurora.org> wrote: > Hi Jonathan, > > On 7/17/2017 10:23 AM, Jonathan Cameron wrote: > > On Mon, 17 Jul 2017 14:06:42 +0100 > > John Garry <john.garry@huawei.com> wrote: > > > >> + > >> > >> On 29/06/2017 03:08, Leizhen (ThunderTown) wrote: > >>> > >>> > >>> On 2017/6/28 17:32, Will Deacon wrote: > >>>> Hi Zhen Lei, > >>>> > >>>> Nate (CC'd), Robin and I have been working on something very similar to > >>>> this series, but this patch is different to what we had planned. More below. > >>>> > >>>> On Mon, Jun 26, 2017 at 09:38:46PM +0800, Zhen Lei wrote: > >>>>> Because all TLBI commands should be followed by a SYNC command, to make > >>>>> sure that it has been completely finished. So we can just add the TLBI > >>>>> commands into the queue, and put off the execution until meet SYNC or > >>>>> other commands. To prevent the followed SYNC command waiting for a long > >>>>> time because of too many commands have been delayed, restrict the max > >>>>> delayed number. > >>>>> > >>>>> According to my test, I got the same performance data as I replaced writel > >>>>> with writel_relaxed in queue_inc_prod. > >>>>> > >>>>> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> > >>>>> --- > >>>>> drivers/iommu/arm-smmu-v3.c | 42 +++++++++++++++++++++++++++++++++++++----- > >>>>> 1 file changed, 37 insertions(+), 5 deletions(-) > >>>>> > >>>>> diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c > >>>>> index 291da5f..4481123 100644 > >>>>> --- a/drivers/iommu/arm-smmu-v3.c > >>>>> +++ b/drivers/iommu/arm-smmu-v3.c > >>>>> @@ -337,6 +337,7 @@ > >>>>> /* Command queue */ > >>>>> #define CMDQ_ENT_DWORDS 2 > >>>>> #define CMDQ_MAX_SZ_SHIFT 8 > >>>>> +#define CMDQ_MAX_DELAYED 32 > >>>>> > >>>>> #define CMDQ_ERR_SHIFT 24 > >>>>> #define CMDQ_ERR_MASK 0x7f > >>>>> @@ -472,6 +473,7 @@ struct arm_smmu_cmdq_ent { > >>>>> }; > >>>>> } cfgi; > >>>>> > >>>>> + #define CMDQ_OP_TLBI_NH_ALL 0x10 > >>>>> #define CMDQ_OP_TLBI_NH_ASID 0x11 > >>>>> #define CMDQ_OP_TLBI_NH_VA 0x12 > >>>>> #define CMDQ_OP_TLBI_EL2_ALL 0x20 > >>>>> @@ -499,6 +501,7 @@ struct arm_smmu_cmdq_ent { > >>>>> > >>>>> struct arm_smmu_queue { > >>>>> int irq; /* Wired interrupt */ > >>>>> + u32 nr_delay; > >>>>> > >>>>> __le64 *base; > >>>>> dma_addr_t base_dma; > >>>>> @@ -722,11 +725,16 @@ static int queue_sync_prod(struct arm_smmu_queue *q) > >>>>> return ret; > >>>>> } > >>>>> > >>>>> -static void queue_inc_prod(struct arm_smmu_queue *q) > >>>>> +static void queue_inc_swprod(struct arm_smmu_queue *q) > >>>>> { > >>>>> - u32 prod = (Q_WRP(q, q->prod) | Q_IDX(q, q->prod)) + 1; > >>>>> + u32 prod = q->prod + 1; > >>>>> > >>>>> q->prod = Q_OVF(q, q->prod) | Q_WRP(q, prod) | Q_IDX(q, prod); > >>>>> +} > >>>>> + > >>>>> +static void queue_inc_prod(struct arm_smmu_queue *q) > >>>>> +{ > >>>>> + queue_inc_swprod(q); > >>>>> writel(q->prod, q->prod_reg); > >>>>> } > >>>>> > >>>>> @@ -761,13 +769,24 @@ static void queue_write(__le64 *dst, u64 *src, size_t n_dwords) > >>>>> *dst++ = cpu_to_le64(*src++); > >>>>> } > >>>>> > >>>>> -static int queue_insert_raw(struct arm_smmu_queue *q, u64 *ent) > >>>>> +static int queue_insert_raw(struct arm_smmu_queue *q, u64 *ent, int optimize) > >>>>> { > >>>>> if (queue_full(q)) > >>>>> return -ENOSPC; > >>>>> > >>>>> queue_write(Q_ENT(q, q->prod), ent, q->ent_dwords); > >>>>> - queue_inc_prod(q); > >>>>> + > >>>>> + /* > >>>>> + * We don't want too many commands to be delayed, this may lead the > >>>>> + * followed sync command to wait for a long time. > >>>>> + */ > >>>>> + if (optimize && (++q->nr_delay < CMDQ_MAX_DELAYED)) { > >>>>> + queue_inc_swprod(q); > >>>>> + } else { > >>>>> + queue_inc_prod(q); > >>>>> + q->nr_delay = 0; > >>>>> + } > >>>>> + > >>>> > >>>> So here, you're effectively putting invalidation commands into the command > >>>> queue without updating PROD. Do you actually see a performance advantage > >>>> from doing so? Another side of the argument would be that we should be > >>> Yes, my sas ssd performance test showed that it can improve about 100-150K/s(the same to I directly replace > >>> writel with writel_relaxed). And the average execution time of iommu_unmap(which called by iommu_dma_unmap_sg) > >>> dropped from 10us to 5us. > >>> > >>>> moving PROD as soon as we can, so that the SMMU can process invalidation > >>>> commands in the background and reduce the cost of the final SYNC operation > >>>> when the high-level unmap operation is complete. > >>> There maybe that __iowmb() is more expensive than wait for tlbi complete. Except the time of __iowmb() > >>> itself, it also protected by spinlock, lock confliction will rise rapidly in the stress scene. __iowmb() > >>> average cost 300-500ns(Sorry, I forget the exact value). > >>> > >>> In addition, after applied this patcheset and Robin's v2, and my earlier dma64 iova optimization patchset. > >>> Our net performance test got the same data to global bypass. But sas ssd still have more than 20% dropped. > >>> Maybe we should still focus at map/unamp, because the average execution time of iova alloc/free is only > >>> about 400ns. > >>> > >>> By the way, patch2-5 is more effective than this one, it can improve more than 350K/s. And with it, we can > >>> got about 100-150K/s improvement of Robin's v2. Otherwise, I saw non effective of Robin's v2. Sorry, I have > >>> not tested how about this patch without patch2-5. Further more, I got the same performance data to global > >>> bypass for the traditional mechanical hard disk with only patch2-5(without this patch and Robin's). > >>> > > Hi All, > > > > I'm a bit of late entry to this discussion. Just been running some more > > detailed tests on our d05 boards and wanted to bring some more numbers to > > the discussion. > > > > All tests against 4.12 with the following additions: > > * Robin's series removing the io-pgtable spinlock (and a few recent fixes) > > * Cherry picked updates to the sas driver, merged prior to 4.13-rc1 > > * An additional HNS (network card) bug fix that will be upstreamed shortly. > > > > I've broken the results down into this patch and this patch + the remainder > > of the set. As leizhen mentioned we got a nice little performance > > bump from Robin's series so that was applied first (as it's in mainline now) > > > > SAS tests were fio with noop scheduler, 4k block size and various io depths > > 1 process per disk. Note this is probably a different setup to leizhen's > > original numbers. > > > > Precentages are off the performance seen with the smmu disabled. > > SAS > > 4.12 - none of this series. > > SMMU disabled > > read io-depth 32 - 384K IOPS (100%) > > read io-depth 2048 - 950K IOPS (100%) > > rw io-depth 32 - 166K IOPS (100%) > > rw io-depth 2048 - 340K IOPS (100%) > > > > SMMU enabled > > read io-depth 32 - 201K IOPS (52%) > > read io-depth 2048 - 306K IOPS (32%) > > rw io-depth 32 - 99K IOPS (60%) > > rw io-depth 2048 - 150K IOPS (44%) > > > > Robin's recent series with fixes as seen on list (now merged) > > SMMU enabled. > > read io-depth 32 - 208K IOPS (54%) > > read io-depth 2048 - 335K IOPS (35%) > > rw io-depth 32 - 105K IOPS (63%) > > rw io-depth 2048 - 165K IOPS (49%) > > > > 4.12 + Robin's series + just this patch SMMU enabled > > > > (iommu/arm-smmu-v3: put of the execution of TLBI* to reduce lock conflict) > > > > read io-depth 32 - 225K IOPS (59%) > > read io-depth 2048 - 365K IOPS (38%) > > rw io-depth 32 - 110K IOPS (66%) > > rw io-depth 2048 - 179K IOPS (53%) > > > > 4.12 + Robin's series + Second part of this series > > > > (iommu/arm-smmu-v3: put of the execution of TLBI* to reduce lock conflict) > > (iommu: add a new member unmap_tlb_sync into struct iommu_ops) > > (iommu/arm-smmu-v3: add supprot for unmap an iova range with only on tlb sync) > > (iommu/arm-smmu: add support for unmap of a memory range with only one tlb sync) > > > > read io-depth 32 - 225K IOPS (59%) > > read io-depth 2048 - 833K IOPS (88%) > > rw io-depth 32 - 112K IOPS (67%) > > rw io-depth 2048 - 220K IOPS (65%) > > > > Robin's series gave us small gains across the board (3-5% recovered) > > relative to the no smmu performance (which we are taking as the ideal case) > > > > This first patch gets us back another 2-5% of the no smmu performance > > > > The next few patches get us very little advantage on the small io-depths > > but make a large difference to the larger io-depths - in particular the > > read IOPS which is over twice as fast as without the series. > > > > For HNS it seems that we are less dependent on the SMMU performance and > > can reach the non SMMU speed. > > > > Tests with > > iperf -t 30 -i 10 -c IPADDRESS -P 3 last 10 seconds taken to avoid any > > initial variability. > > > > The server end of the link was always running with smmu v3 disabled > > so as to act as a fast sink of the data. Some variation seen across > > repeat runs. > > > > Mainline v4.12 + network card fix > > NO SMMU > > 9.42 GBits/sec > > > > SMMU > > 4.36 GBits/sec (46%) > > > > Robin's io-pgtable spinlock series > > > > 6.68 to 7.34 (71% - 78% variation across runs) > > > > Just this patch SMMU enabled > > > > (iommu/arm-smmu-v3: put of the execution of TLBI* to reduce lock conflict) > > > > 7.96-8.8 GBits/sec (85% - 94% some variation across runs) > > > > Full series > > > > (iommu/arm-smmu-v3: put of the execution of TLBI* to reduce lock conflict) > > (iommu: add a new member unmap_tlb_sync into struct iommu_ops) > > (iommu/arm-smmu-v3: add supprot for unmap an iova range with only on tlb sync) > > (iommu/arm-smmu: add support for unmap of a memory range with only one tlb sync) > > > > 9.42 GBits/Sec (100%) > > > > So HNS test shows a greater boost from Robin's series and this first patch. > > This is most likely because the HNS test is not putting as high a load on > > the SMMU and associated code as the SAS test. > > > > In both cases however, this shows that both parts of this patch > > series are beneficial. > > > > So on to the questions ;) > > > > Will, you mentioned that along with Robin and Nate you were working on > > a somewhat related strategy to improve the performance. Any ETA on that? > > The strategy I was working on is basically equivalent to the second > part of the series. I will test your patches out sometime this week, and > I'll also try to have our performance team run it through their whole > suite. Thanks, that's excellent. Look forward to hearing how it goes. Particularly useful would be to know if there are particular performance tests that show up anything interesting that we might want to replicate. Jonathan and Leizhen > > > > > As you might imagine, with the above numbers we are very keen to try and > > move forward with this as quickly as possible. > > > > If you want additional testing we would be happy to help. > > > > Thanks, > > > > Jonathan > > > > > > > >>>> > >>>> Will > >>>> > >>>> . > >>>> > >>> > >> > >> > > > > >
Hi Jonathan, [...] >>>>> >>> Hi All, >>> >>> I'm a bit of late entry to this discussion. Just been running some more >>> detailed tests on our d05 boards and wanted to bring some more numbers to >>> the discussion. >>> >>> All tests against 4.12 with the following additions: >>> * Robin's series removing the io-pgtable spinlock (and a few recent fixes) >>> * Cherry picked updates to the sas driver, merged prior to 4.13-rc1 >>> * An additional HNS (network card) bug fix that will be upstreamed shortly. >>> >>> I've broken the results down into this patch and this patch + the remainder >>> of the set. As leizhen mentioned we got a nice little performance >>> bump from Robin's series so that was applied first (as it's in mainline now) >>> >>> SAS tests were fio with noop scheduler, 4k block size and various io depths >>> 1 process per disk. Note this is probably a different setup to leizhen's >>> original numbers. >>> >>> Precentages are off the performance seen with the smmu disabled. >>> SAS >>> 4.12 - none of this series. >>> SMMU disabled >>> read io-depth 32 - 384K IOPS (100%) >>> read io-depth 2048 - 950K IOPS (100%) >>> rw io-depth 32 - 166K IOPS (100%) >>> rw io-depth 2048 - 340K IOPS (100%) >>> >>> SMMU enabled >>> read io-depth 32 - 201K IOPS (52%) >>> read io-depth 2048 - 306K IOPS (32%) >>> rw io-depth 32 - 99K IOPS (60%) >>> rw io-depth 2048 - 150K IOPS (44%) >>> >>> Robin's recent series with fixes as seen on list (now merged) >>> SMMU enabled. >>> read io-depth 32 - 208K IOPS (54%) >>> read io-depth 2048 - 335K IOPS (35%) >>> rw io-depth 32 - 105K IOPS (63%) >>> rw io-depth 2048 - 165K IOPS (49%) >>> >>> 4.12 + Robin's series + just this patch SMMU enabled >>> >>> (iommu/arm-smmu-v3: put of the execution of TLBI* to reduce lock conflict) >>> >>> read io-depth 32 - 225K IOPS (59%) >>> read io-depth 2048 - 365K IOPS (38%) >>> rw io-depth 32 - 110K IOPS (66%) >>> rw io-depth 2048 - 179K IOPS (53%) >>> >>> 4.12 + Robin's series + Second part of this series >>> >>> (iommu/arm-smmu-v3: put of the execution of TLBI* to reduce lock conflict) >>> (iommu: add a new member unmap_tlb_sync into struct iommu_ops) >>> (iommu/arm-smmu-v3: add supprot for unmap an iova range with only on tlb sync) >>> (iommu/arm-smmu: add support for unmap of a memory range with only one tlb sync) >>> >>> read io-depth 32 - 225K IOPS (59%) >>> read io-depth 2048 - 833K IOPS (88%) >>> rw io-depth 32 - 112K IOPS (67%) >>> rw io-depth 2048 - 220K IOPS (65%) >>> >>> Robin's series gave us small gains across the board (3-5% recovered) >>> relative to the no smmu performance (which we are taking as the ideal case) >>> >>> This first patch gets us back another 2-5% of the no smmu performance >>> >>> The next few patches get us very little advantage on the small io-depths >>> but make a large difference to the larger io-depths - in particular the >>> read IOPS which is over twice as fast as without the series. >>> >>> For HNS it seems that we are less dependent on the SMMU performance and >>> can reach the non SMMU speed. >>> >>> Tests with >>> iperf -t 30 -i 10 -c IPADDRESS -P 3 last 10 seconds taken to avoid any >>> initial variability. >>> >>> The server end of the link was always running with smmu v3 disabled >>> so as to act as a fast sink of the data. Some variation seen across >>> repeat runs. >>> >>> Mainline v4.12 + network card fix >>> NO SMMU >>> 9.42 GBits/sec >>> >>> SMMU >>> 4.36 GBits/sec (46%) >>> >>> Robin's io-pgtable spinlock series >>> >>> 6.68 to 7.34 (71% - 78% variation across runs) >>> >>> Just this patch SMMU enabled >>> >>> (iommu/arm-smmu-v3: put of the execution of TLBI* to reduce lock conflict) >>> >>> 7.96-8.8 GBits/sec (85% - 94% some variation across runs) >>> >>> Full series >>> >>> (iommu/arm-smmu-v3: put of the execution of TLBI* to reduce lock conflict) >>> (iommu: add a new member unmap_tlb_sync into struct iommu_ops) >>> (iommu/arm-smmu-v3: add supprot for unmap an iova range with only on tlb sync) >>> (iommu/arm-smmu: add support for unmap of a memory range with only one tlb sync) >>> >>> 9.42 GBits/Sec (100%) >>> >>> So HNS test shows a greater boost from Robin's series and this first patch. >>> This is most likely because the HNS test is not putting as high a load on >>> the SMMU and associated code as the SAS test. >>> >>> In both cases however, this shows that both parts of this patch >>> series are beneficial. >>> >>> So on to the questions ;) >>> >>> Will, you mentioned that along with Robin and Nate you were working on >>> a somewhat related strategy to improve the performance. Any ETA on that? >> >> The strategy I was working on is basically equivalent to the second >> part of the series. I will test your patches out sometime this week, and >> I'll also try to have our performance team run it through their whole >> suite. > > Thanks, that's excellent. Look forward to hearing how it goes. I tested the patches with 4 NVME drives connected to a single SMMU and the results seem to be inline with those you've reported. FIO - 512k blocksize / io-depth 32 / 1 thread per drive Baseline 4.13-rc1 w/SMMU enabled: 25% of SMMU bypass performance Baseline + Patch 1 : 28% Baseline + Patches 2-5 : 86% Baseline + Complete series : 100% [!!] I saw performance improvements across all of the other FIO profiles I tested, although not always as substantial as was seen in the 512k/32/1 case. The performance of some of the profiles, especially those with many threads per drive, remains woeful (often below 20%), but hopefully Robin's iova series will help improve that. > > Particularly useful would be to know if there are particular performance tests > that show up anything interesting that we might want to replicate. > > Jonathan and Leizhen >> >>> >>> As you might imagine, with the above numbers we are very keen to try and >>> move forward with this as quickly as possible. >>> >>> If you want additional testing we would be happy to help. >>> >>> Thanks, >>> >>> Jonathan [...] -Nate -- Qualcomm Datacenter Technologies as an affiliate of Qualcomm Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.
On Thu, 20 Jul 2017 15:07:05 -0400 Nate Watterson <nwatters@codeaurora.org> wrote: > Hi Jonathan, > > [...] > >>>>> > >>> Hi All, > >>> > >>> I'm a bit of late entry to this discussion. Just been running some more > >>> detailed tests on our d05 boards and wanted to bring some more numbers to > >>> the discussion. > >>> > >>> All tests against 4.12 with the following additions: > >>> * Robin's series removing the io-pgtable spinlock (and a few recent fixes) > >>> * Cherry picked updates to the sas driver, merged prior to 4.13-rc1 > >>> * An additional HNS (network card) bug fix that will be upstreamed shortly. > >>> > >>> I've broken the results down into this patch and this patch + the remainder > >>> of the set. As leizhen mentioned we got a nice little performance > >>> bump from Robin's series so that was applied first (as it's in mainline now) > >>> > >>> SAS tests were fio with noop scheduler, 4k block size and various io depths > >>> 1 process per disk. Note this is probably a different setup to leizhen's > >>> original numbers. > >>> > >>> Precentages are off the performance seen with the smmu disabled. > >>> SAS > >>> 4.12 - none of this series. > >>> SMMU disabled > >>> read io-depth 32 - 384K IOPS (100%) > >>> read io-depth 2048 - 950K IOPS (100%) > >>> rw io-depth 32 - 166K IOPS (100%) > >>> rw io-depth 2048 - 340K IOPS (100%) > >>> > >>> SMMU enabled > >>> read io-depth 32 - 201K IOPS (52%) > >>> read io-depth 2048 - 306K IOPS (32%) > >>> rw io-depth 32 - 99K IOPS (60%) > >>> rw io-depth 2048 - 150K IOPS (44%) > >>> > >>> Robin's recent series with fixes as seen on list (now merged) > >>> SMMU enabled. > >>> read io-depth 32 - 208K IOPS (54%) > >>> read io-depth 2048 - 335K IOPS (35%) > >>> rw io-depth 32 - 105K IOPS (63%) > >>> rw io-depth 2048 - 165K IOPS (49%) > >>> > >>> 4.12 + Robin's series + just this patch SMMU enabled > >>> > >>> (iommu/arm-smmu-v3: put of the execution of TLBI* to reduce lock conflict) > >>> > >>> read io-depth 32 - 225K IOPS (59%) > >>> read io-depth 2048 - 365K IOPS (38%) > >>> rw io-depth 32 - 110K IOPS (66%) > >>> rw io-depth 2048 - 179K IOPS (53%) > >>> > >>> 4.12 + Robin's series + Second part of this series > >>> > >>> (iommu/arm-smmu-v3: put of the execution of TLBI* to reduce lock conflict) > >>> (iommu: add a new member unmap_tlb_sync into struct iommu_ops) > >>> (iommu/arm-smmu-v3: add supprot for unmap an iova range with only on tlb sync) > >>> (iommu/arm-smmu: add support for unmap of a memory range with only one tlb sync) > >>> > >>> read io-depth 32 - 225K IOPS (59%) > >>> read io-depth 2048 - 833K IOPS (88%) > >>> rw io-depth 32 - 112K IOPS (67%) > >>> rw io-depth 2048 - 220K IOPS (65%) > >>> > >>> Robin's series gave us small gains across the board (3-5% recovered) > >>> relative to the no smmu performance (which we are taking as the ideal case) > >>> > >>> This first patch gets us back another 2-5% of the no smmu performance > >>> > >>> The next few patches get us very little advantage on the small io-depths > >>> but make a large difference to the larger io-depths - in particular the > >>> read IOPS which is over twice as fast as without the series. > >>> > >>> For HNS it seems that we are less dependent on the SMMU performance and > >>> can reach the non SMMU speed. > >>> > >>> Tests with > >>> iperf -t 30 -i 10 -c IPADDRESS -P 3 last 10 seconds taken to avoid any > >>> initial variability. > >>> > >>> The server end of the link was always running with smmu v3 disabled > >>> so as to act as a fast sink of the data. Some variation seen across > >>> repeat runs. > >>> > >>> Mainline v4.12 + network card fix > >>> NO SMMU > >>> 9.42 GBits/sec > >>> > >>> SMMU > >>> 4.36 GBits/sec (46%) > >>> > >>> Robin's io-pgtable spinlock series > >>> > >>> 6.68 to 7.34 (71% - 78% variation across runs) > >>> > >>> Just this patch SMMU enabled > >>> > >>> (iommu/arm-smmu-v3: put of the execution of TLBI* to reduce lock conflict) > >>> > >>> 7.96-8.8 GBits/sec (85% - 94% some variation across runs) > >>> > >>> Full series > >>> > >>> (iommu/arm-smmu-v3: put of the execution of TLBI* to reduce lock conflict) > >>> (iommu: add a new member unmap_tlb_sync into struct iommu_ops) > >>> (iommu/arm-smmu-v3: add supprot for unmap an iova range with only on tlb sync) > >>> (iommu/arm-smmu: add support for unmap of a memory range with only one tlb sync) > >>> > >>> 9.42 GBits/Sec (100%) > >>> > >>> So HNS test shows a greater boost from Robin's series and this first patch. > >>> This is most likely because the HNS test is not putting as high a load on > >>> the SMMU and associated code as the SAS test. > >>> > >>> In both cases however, this shows that both parts of this patch > >>> series are beneficial. > >>> > >>> So on to the questions ;) > >>> > >>> Will, you mentioned that along with Robin and Nate you were working on > >>> a somewhat related strategy to improve the performance. Any ETA on that? > >> > >> The strategy I was working on is basically equivalent to the second > >> part of the series. I will test your patches out sometime this week, and > >> I'll also try to have our performance team run it through their whole > >> suite. > > > > Thanks, that's excellent. Look forward to hearing how it goes. > > I tested the patches with 4 NVME drives connected to a single SMMU and > the results seem to be inline with those you've reported. > > FIO - 512k blocksize / io-depth 32 / 1 thread per drive > Baseline 4.13-rc1 w/SMMU enabled: 25% of SMMU bypass performance > Baseline + Patch 1 : 28% > Baseline + Patches 2-5 : 86% > Baseline + Complete series : 100% [!!] > > I saw performance improvements across all of the other FIO profiles I > tested, although not always as substantial as was seen in the 512k/32/1 > case. The performance of some of the profiles, especially those with > many threads per drive, remains woeful (often below 20%), but hopefully > Robin's iova series will help improve that. Excellent. Thanks for the info and running the tests. Even with both series we are still seeing some reduction in over the no-smmu performance, but to a much lesser extent. Jonathan > > > > > Particularly useful would be to know if there are particular performance tests > > that show up anything interesting that we might want to replicate. > > > > Jonathan and Leizhen > >> > >>> > >>> As you might imagine, with the above numbers we are very keen to try and > >>> move forward with this as quickly as possible. > >>> > >>> If you want additional testing we would be happy to help. > >>> > >>> Thanks, > >>> > >>> Jonathan > [...] > > -Nate >
On Mon, Jun 26, 2017 at 09:38:46PM +0800, Zhen Lei wrote: > -static int queue_insert_raw(struct arm_smmu_queue *q, u64 *ent) > +static int queue_insert_raw(struct arm_smmu_queue *q, u64 *ent, int optimize) > { > if (queue_full(q)) > return -ENOSPC; > > queue_write(Q_ENT(q, q->prod), ent, q->ent_dwords); > - queue_inc_prod(q); > + > + /* > + * We don't want too many commands to be delayed, this may lead the > + * followed sync command to wait for a long time. > + */ > + if (optimize && (++q->nr_delay < CMDQ_MAX_DELAYED)) { > + queue_inc_swprod(q); > + } else { > + queue_inc_prod(q); > + q->nr_delay = 0; > + } > + > return 0; > } > > @@ -909,6 +928,7 @@ static void arm_smmu_cmdq_skip_err(struct arm_smmu_device *smmu) > static void arm_smmu_cmdq_issue_cmd(struct arm_smmu_device *smmu, > struct arm_smmu_cmdq_ent *ent) > { > + int optimize = 0; > u64 cmd[CMDQ_ENT_DWORDS]; > unsigned long flags; > bool wfe = !!(smmu->features & ARM_SMMU_FEAT_SEV); > @@ -920,8 +940,17 @@ static void arm_smmu_cmdq_issue_cmd(struct arm_smmu_device *smmu, > return; > } > > + /* > + * All TLBI commands should be followed by a sync command later. > + * The CFGI commands is the same, but they are rarely executed. > + * So just optimize TLBI commands now, to reduce the "if" judgement. > + */ > + if ((ent->opcode >= CMDQ_OP_TLBI_NH_ALL) && > + (ent->opcode <= CMDQ_OP_TLBI_NSNH_ALL)) > + optimize = 1; > + > spin_lock_irqsave(&smmu->cmdq.lock, flags); > - while (queue_insert_raw(q, cmd) == -ENOSPC) { > + while (queue_insert_raw(q, cmd, optimize) == -ENOSPC) { > if (queue_poll_cons(q, false, wfe)) > dev_err_ratelimited(smmu->dev, "CMDQ timeout\n"); > } This doesn't look correct. How do you make sure that a given IOVA range is flushed before the addresses are reused? Regards, Joerg
On 2017/8/22 23:41, Joerg Roedel wrote: > On Mon, Jun 26, 2017 at 09:38:46PM +0800, Zhen Lei wrote: >> -static int queue_insert_raw(struct arm_smmu_queue *q, u64 *ent) >> +static int queue_insert_raw(struct arm_smmu_queue *q, u64 *ent, int optimize) >> { >> if (queue_full(q)) >> return -ENOSPC; >> >> queue_write(Q_ENT(q, q->prod), ent, q->ent_dwords); >> - queue_inc_prod(q); >> + >> + /* >> + * We don't want too many commands to be delayed, this may lead the >> + * followed sync command to wait for a long time. >> + */ >> + if (optimize && (++q->nr_delay < CMDQ_MAX_DELAYED)) { >> + queue_inc_swprod(q); >> + } else { >> + queue_inc_prod(q); >> + q->nr_delay = 0; >> + } >> + >> return 0; >> } >> >> @@ -909,6 +928,7 @@ static void arm_smmu_cmdq_skip_err(struct arm_smmu_device *smmu) >> static void arm_smmu_cmdq_issue_cmd(struct arm_smmu_device *smmu, >> struct arm_smmu_cmdq_ent *ent) >> { >> + int optimize = 0; >> u64 cmd[CMDQ_ENT_DWORDS]; >> unsigned long flags; >> bool wfe = !!(smmu->features & ARM_SMMU_FEAT_SEV); >> @@ -920,8 +940,17 @@ static void arm_smmu_cmdq_issue_cmd(struct arm_smmu_device *smmu, >> return; >> } >> >> + /* >> + * All TLBI commands should be followed by a sync command later. >> + * The CFGI commands is the same, but they are rarely executed. >> + * So just optimize TLBI commands now, to reduce the "if" judgement. >> + */ >> + if ((ent->opcode >= CMDQ_OP_TLBI_NH_ALL) && >> + (ent->opcode <= CMDQ_OP_TLBI_NSNH_ALL)) >> + optimize = 1; >> + >> spin_lock_irqsave(&smmu->cmdq.lock, flags); >> - while (queue_insert_raw(q, cmd) == -ENOSPC) { >> + while (queue_insert_raw(q, cmd, optimize) == -ENOSPC) { >> if (queue_poll_cons(q, false, wfe)) >> dev_err_ratelimited(smmu->dev, "CMDQ timeout\n"); >> } > > This doesn't look correct. How do you make sure that a given IOVA range > is flushed before the addresses are reused? Hi, Joerg: It's actullay guaranteed by the upper layer functions, for example: static int arm_lpae_unmap( ... unmapped = __arm_lpae_unmap(data, iova, size, lvl, ptep); //__arm_lpae_unmap will indirectly call arm_smmu_cmdq_issue_cmd to invalidate tlbs if (unmapped) io_pgtable_tlb_sync(&data->iop); //a tlb_sync wait all tlbi operations finished I also described it in the next patch(2/5). Showed below: Some people might ask: Is it safe to do so? The answer is yes. The standard processing flow is: alloc iova map process data unmap tlb invalidation and sync free iova What should be guaranteed is: "free iova" action is behind "unmap" and "tlbi operation" action, that is what we are doing right now. This ensures that: all TLBs of an iova-range have been invalidated before the iova reallocated. Best regards, LeiZhen > > > Regards, > > Joerg > > > . > -- Thanks! BestRegards
diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c index 291da5f..4481123 100644 --- a/drivers/iommu/arm-smmu-v3.c +++ b/drivers/iommu/arm-smmu-v3.c @@ -337,6 +337,7 @@ /* Command queue */ #define CMDQ_ENT_DWORDS 2 #define CMDQ_MAX_SZ_SHIFT 8 +#define CMDQ_MAX_DELAYED 32 #define CMDQ_ERR_SHIFT 24 #define CMDQ_ERR_MASK 0x7f @@ -472,6 +473,7 @@ struct arm_smmu_cmdq_ent { }; } cfgi; + #define CMDQ_OP_TLBI_NH_ALL 0x10 #define CMDQ_OP_TLBI_NH_ASID 0x11 #define CMDQ_OP_TLBI_NH_VA 0x12 #define CMDQ_OP_TLBI_EL2_ALL 0x20 @@ -499,6 +501,7 @@ struct arm_smmu_cmdq_ent { struct arm_smmu_queue { int irq; /* Wired interrupt */ + u32 nr_delay; __le64 *base; dma_addr_t base_dma; @@ -722,11 +725,16 @@ static int queue_sync_prod(struct arm_smmu_queue *q) return ret; } -static void queue_inc_prod(struct arm_smmu_queue *q) +static void queue_inc_swprod(struct arm_smmu_queue *q) { - u32 prod = (Q_WRP(q, q->prod) | Q_IDX(q, q->prod)) + 1; + u32 prod = q->prod + 1; q->prod = Q_OVF(q, q->prod) | Q_WRP(q, prod) | Q_IDX(q, prod); +} + +static void queue_inc_prod(struct arm_smmu_queue *q) +{ + queue_inc_swprod(q); writel(q->prod, q->prod_reg); } @@ -761,13 +769,24 @@ static void queue_write(__le64 *dst, u64 *src, size_t n_dwords) *dst++ = cpu_to_le64(*src++); } -static int queue_insert_raw(struct arm_smmu_queue *q, u64 *ent) +static int queue_insert_raw(struct arm_smmu_queue *q, u64 *ent, int optimize) { if (queue_full(q)) return -ENOSPC; queue_write(Q_ENT(q, q->prod), ent, q->ent_dwords); - queue_inc_prod(q); + + /* + * We don't want too many commands to be delayed, this may lead the + * followed sync command to wait for a long time. + */ + if (optimize && (++q->nr_delay < CMDQ_MAX_DELAYED)) { + queue_inc_swprod(q); + } else { + queue_inc_prod(q); + q->nr_delay = 0; + } + return 0; } @@ -909,6 +928,7 @@ static void arm_smmu_cmdq_skip_err(struct arm_smmu_device *smmu) static void arm_smmu_cmdq_issue_cmd(struct arm_smmu_device *smmu, struct arm_smmu_cmdq_ent *ent) { + int optimize = 0; u64 cmd[CMDQ_ENT_DWORDS]; unsigned long flags; bool wfe = !!(smmu->features & ARM_SMMU_FEAT_SEV); @@ -920,8 +940,17 @@ static void arm_smmu_cmdq_issue_cmd(struct arm_smmu_device *smmu, return; } + /* + * All TLBI commands should be followed by a sync command later. + * The CFGI commands is the same, but they are rarely executed. + * So just optimize TLBI commands now, to reduce the "if" judgement. + */ + if ((ent->opcode >= CMDQ_OP_TLBI_NH_ALL) && + (ent->opcode <= CMDQ_OP_TLBI_NSNH_ALL)) + optimize = 1; + spin_lock_irqsave(&smmu->cmdq.lock, flags); - while (queue_insert_raw(q, cmd) == -ENOSPC) { + while (queue_insert_raw(q, cmd, optimize) == -ENOSPC) { if (queue_poll_cons(q, false, wfe)) dev_err_ratelimited(smmu->dev, "CMDQ timeout\n"); } @@ -1953,6 +1982,8 @@ static int arm_smmu_init_one_queue(struct arm_smmu_device *smmu, << Q_BASE_LOG2SIZE_SHIFT; q->prod = q->cons = 0; + q->nr_delay = 0; + return 0; } @@ -2512,6 +2543,7 @@ static int arm_smmu_device_hw_probe(struct arm_smmu_device *smmu) dev_err(smmu->dev, "unit-length command queue not supported\n"); return -ENXIO; } + BUILD_BUG_ON(CMDQ_MAX_DELAYED >= (1 << CMDQ_MAX_SZ_SHIFT)); smmu->evtq.q.max_n_shift = min((u32)EVTQ_MAX_SZ_SHIFT, reg >> IDR1_EVTQ_SHIFT & IDR1_EVTQ_MASK);
Because all TLBI commands should be followed by a SYNC command, to make sure that it has been completely finished. So we can just add the TLBI commands into the queue, and put off the execution until meet SYNC or other commands. To prevent the followed SYNC command waiting for a long time because of too many commands have been delayed, restrict the max delayed number. According to my test, I got the same performance data as I replaced writel with writel_relaxed in queue_inc_prod. Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> --- drivers/iommu/arm-smmu-v3.c | 42 +++++++++++++++++++++++++++++++++++++----- 1 file changed, 37 insertions(+), 5 deletions(-) -- 2.5.0