| Message ID | 1395436655-21670-3-git-send-email-john.stultz@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
On Fri 21-03-14 14:17:32, John Stultz wrote: > Users of volatile ranges will need to know if memory was discarded. > This patch adds the purged state tracking required to inform userland > when it marks memory as non-volatile that some memory in that range > was purged and needs to be regenerated. > > This simplified implementation which uses some of the logic from > Minchan's earlier efforts, so credit to Minchan for his work. > > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Android Kernel Team <kernel-team@android.com> > Cc: Johannes Weiner <hannes@cmpxchg.org> > Cc: Robert Love <rlove@google.com> > Cc: Mel Gorman <mel@csn.ul.ie> > Cc: Hugh Dickins <hughd@google.com> > Cc: Dave Hansen <dave@sr71.net> > Cc: Rik van Riel <riel@redhat.com> > Cc: Dmitry Adamushko <dmitry.adamushko@gmail.com> > Cc: Neil Brown <neilb@suse.de> > Cc: Andrea Arcangeli <aarcange@redhat.com> > Cc: Mike Hommey <mh@glandium.org> > Cc: Taras Glek <tglek@mozilla.com> > Cc: Jan Kara <jack@suse.cz> > Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> > Cc: Michel Lespinasse <walken@google.com> > Cc: Minchan Kim <minchan@kernel.org> > Cc: linux-mm@kvack.org <linux-mm@kvack.org> > Signed-off-by: John Stultz <john.stultz@linaro.org> Just one minor nit below. Otherwise the patch looks good to me. So you can add Acked-by: Jan Kara <jack@suse.cz> Honza > --- > include/linux/swap.h | 15 ++++++++-- > include/linux/swapops.h | 10 +++++++ > include/linux/vrange.h | 3 ++ > mm/vrange.c | 75 +++++++++++++++++++++++++++++++++++++++++++++++++ > 4 files changed, 101 insertions(+), 2 deletions(-) > > diff --git a/include/linux/swap.h b/include/linux/swap.h > index 46ba0c6..18c12f9 100644 > --- a/include/linux/swap.h > +++ b/include/linux/swap.h > @@ -70,8 +70,19 @@ static inline int current_is_kswapd(void) > #define SWP_HWPOISON_NUM 0 > #endif > > -#define MAX_SWAPFILES \ > - ((1 << MAX_SWAPFILES_SHIFT) - SWP_MIGRATION_NUM - SWP_HWPOISON_NUM) > + > +/* > + * Purged volatile range pages > + */ > +#define SWP_VRANGE_PURGED_NUM 1 > +#define SWP_VRANGE_PURGED (MAX_SWAPFILES + SWP_HWPOISON_NUM + SWP_MIGRATION_NUM) > + > + > +#define MAX_SWAPFILES ((1 << MAX_SWAPFILES_SHIFT) \ > + - SWP_MIGRATION_NUM \ > + - SWP_HWPOISON_NUM \ > + - SWP_VRANGE_PURGED_NUM \ > + ) > > /* > * Magic header for a swap area. The first part of the union is > diff --git a/include/linux/swapops.h b/include/linux/swapops.h > index c0f7526..84f43d9 100644 > --- a/include/linux/swapops.h > +++ b/include/linux/swapops.h > @@ -161,6 +161,16 @@ static inline int is_write_migration_entry(swp_entry_t entry) > > #endif > > +static inline swp_entry_t make_vpurged_entry(void) > +{ > + return swp_entry(SWP_VRANGE_PURGED, 0); > +} > + > +static inline int is_vpurged_entry(swp_entry_t entry) > +{ > + return swp_type(entry) == SWP_VRANGE_PURGED; > +} > + > #ifdef CONFIG_MEMORY_FAILURE > /* > * Support for hardware poisoned pages > diff --git a/include/linux/vrange.h b/include/linux/vrange.h > index 6e5331e..986fa85 100644 > --- a/include/linux/vrange.h > +++ b/include/linux/vrange.h > @@ -1,6 +1,9 @@ > #ifndef _LINUX_VRANGE_H > #define _LINUX_VRANGE_H > > +#include <linux/swap.h> > +#include <linux/swapops.h> > + > #define VRANGE_NONVOLATILE 0 > #define VRANGE_VOLATILE 1 > #define VRANGE_VALID_FLAGS (0) /* Don't yet support any flags */ > diff --git a/mm/vrange.c b/mm/vrange.c > index 2f8e2ce..1ff3cbd 100644 > --- a/mm/vrange.c > +++ b/mm/vrange.c > @@ -8,6 +8,76 @@ > #include <linux/mm_inline.h> > #include "internal.h" > > +struct vrange_walker { > + struct vm_area_struct *vma; > + int page_was_purged; > +}; > + > + > +/** > + * vrange_check_purged_pte - Checks ptes for purged pages > + * > + * Iterates over the ptes in the pmd checking if they have > + * purged swap entries. > + * > + * Sets the vrange_walker.pages_purged to 1 if any were purged. ^^^ page_was_purged > + */ > +static int vrange_check_purged_pte(pmd_t *pmd, unsigned long addr, > + unsigned long end, struct mm_walk *walk) > +{ > + struct vrange_walker *vw = walk->private; > + pte_t *pte; > + spinlock_t *ptl; > + > + if (pmd_trans_huge(*pmd)) > + return 0; > + if (pmd_trans_unstable(pmd)) > + return 0; > + > + pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl); > + for (; addr != end; pte++, addr += PAGE_SIZE) { > + if (!pte_present(*pte)) { > + swp_entry_t vrange_entry = pte_to_swp_entry(*pte); > + > + if (unlikely(is_vpurged_entry(vrange_entry))) { > + vw->page_was_purged = 1; > + break; > + } > + } > + } > + pte_unmap_unlock(pte - 1, ptl); > + cond_resched(); > + > + return 0; > +} > + > + > +/** > + * vrange_check_purged - Sets up a mm_walk to check for purged pages > + * > + * Sets up and calls wa_page_range() to check for purge pages. > + * > + * Returns 1 if pages in the range were purged, 0 otherwise. > + */ > +static int vrange_check_purged(struct mm_struct *mm, > + struct vm_area_struct *vma, > + unsigned long start, > + unsigned long end) > +{ > + struct vrange_walker vw; > + struct mm_walk vrange_walk = { > + .pmd_entry = vrange_check_purged_pte, > + .mm = vma->vm_mm, > + .private = &vw, > + }; > + vw.page_was_purged = 0; > + vw.vma = vma; > + > + walk_page_range(start, end, &vrange_walk); > + > + return vw.page_was_purged; > + > +} > > /** > * do_vrange - Marks or clears VMAs in the range (start-end) as VM_VOLATILE > @@ -106,6 +176,11 @@ success: > vma = prev->vm_next; > } > out: > + if (count && (mode == VRANGE_NONVOLATILE)) > + *purged = vrange_check_purged(mm, vma, > + orig_start, > + orig_start+count); > + > up_read(&mm->mmap_sem); > > /* report bytes successfully marked, even if we're exiting on error */ > -- > 1.8.3.2 >
On Fri, Mar 21, 2014 at 2:17 PM, John Stultz <john.stultz@linaro.org> wrote: > Users of volatile ranges will need to know if memory was discarded. > This patch adds the purged state tracking required to inform userland > when it marks memory as non-volatile that some memory in that range > was purged and needs to be regenerated. > > This simplified implementation which uses some of the logic from > Minchan's earlier efforts, so credit to Minchan for his work. > > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Android Kernel Team <kernel-team@android.com> > Cc: Johannes Weiner <hannes@cmpxchg.org> > Cc: Robert Love <rlove@google.com> > Cc: Mel Gorman <mel@csn.ul.ie> > Cc: Hugh Dickins <hughd@google.com> > Cc: Dave Hansen <dave@sr71.net> > Cc: Rik van Riel <riel@redhat.com> > Cc: Dmitry Adamushko <dmitry.adamushko@gmail.com> > Cc: Neil Brown <neilb@suse.de> > Cc: Andrea Arcangeli <aarcange@redhat.com> > Cc: Mike Hommey <mh@glandium.org> > Cc: Taras Glek <tglek@mozilla.com> > Cc: Jan Kara <jack@suse.cz> > Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> > Cc: Michel Lespinasse <walken@google.com> > Cc: Minchan Kim <minchan@kernel.org> > Cc: linux-mm@kvack.org <linux-mm@kvack.org> > Signed-off-by: John Stultz <john.stultz@linaro.org> > --- > include/linux/swap.h | 15 ++++++++-- > include/linux/swapops.h | 10 +++++++ > include/linux/vrange.h | 3 ++ > mm/vrange.c | 75 +++++++++++++++++++++++++++++++++++++++++++++++++ > 4 files changed, 101 insertions(+), 2 deletions(-) > > diff --git a/include/linux/swap.h b/include/linux/swap.h > index 46ba0c6..18c12f9 100644 > --- a/include/linux/swap.h > +++ b/include/linux/swap.h > @@ -70,8 +70,19 @@ static inline int current_is_kswapd(void) > #define SWP_HWPOISON_NUM 0 > #endif > > -#define MAX_SWAPFILES \ > - ((1 << MAX_SWAPFILES_SHIFT) - SWP_MIGRATION_NUM - SWP_HWPOISON_NUM) > + > +/* > + * Purged volatile range pages > + */ > +#define SWP_VRANGE_PURGED_NUM 1 > +#define SWP_VRANGE_PURGED (MAX_SWAPFILES + SWP_HWPOISON_NUM + SWP_MIGRATION_NUM) > + > + > +#define MAX_SWAPFILES ((1 << MAX_SWAPFILES_SHIFT) \ > + - SWP_MIGRATION_NUM \ > + - SWP_HWPOISON_NUM \ > + - SWP_VRANGE_PURGED_NUM \ > + ) This change hwpoison and migration tag number. maybe ok, maybe not. I'd suggest to use younger number than hwpoison. (That's why hwpoison uses younger number than migration) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
> +/** > + * vrange_check_purged_pte - Checks ptes for purged pages > + * > + * Iterates over the ptes in the pmd checking if they have > + * purged swap entries. > + * > + * Sets the vrange_walker.pages_purged to 1 if any were purged. > + */ > +static int vrange_check_purged_pte(pmd_t *pmd, unsigned long addr, > + unsigned long end, struct mm_walk *walk) > +{ > + struct vrange_walker *vw = walk->private; > + pte_t *pte; > + spinlock_t *ptl; > + > + if (pmd_trans_huge(*pmd)) > + return 0; > + if (pmd_trans_unstable(pmd)) > + return 0; > + > + pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl); > + for (; addr != end; pte++, addr += PAGE_SIZE) { > + if (!pte_present(*pte)) { > + swp_entry_t vrange_entry = pte_to_swp_entry(*pte); > + > + if (unlikely(is_vpurged_entry(vrange_entry))) { > + vw->page_was_purged = 1; > + break; This function only detect there is vpurge entry or not. But VRANGE_NONVOLATILE should remove all vpurge entries. Otherwise, non-volatiled range still makes SIGBUS. > + } > + } > + } > + pte_unmap_unlock(pte - 1, ptl); > + cond_resched(); > + > + return 0; > +} -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
On Sun, Mar 23, 2014 at 5:29 AM, Jan Kara <jack@suse.cz> wrote: > On Fri 21-03-14 14:17:32, John Stultz wrote: >> + * >> + * Sets the vrange_walker.pages_purged to 1 if any were purged. > ^^^ page_was_purged Doh. Thanks for catching this! Fixed in my tree. Thanks so much for the review! -john -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
On Sun, Mar 23, 2014 at 10:50 AM, KOSAKI Motohiro <kosaki.motohiro@gmail.com> wrote: >> +/** >> + * vrange_check_purged_pte - Checks ptes for purged pages >> + * >> + * Iterates over the ptes in the pmd checking if they have >> + * purged swap entries. >> + * >> + * Sets the vrange_walker.pages_purged to 1 if any were purged. >> + */ >> +static int vrange_check_purged_pte(pmd_t *pmd, unsigned long addr, >> + unsigned long end, struct mm_walk *walk) >> +{ >> + struct vrange_walker *vw = walk->private; >> + pte_t *pte; >> + spinlock_t *ptl; >> + >> + if (pmd_trans_huge(*pmd)) >> + return 0; >> + if (pmd_trans_unstable(pmd)) >> + return 0; >> + >> + pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl); >> + for (; addr != end; pte++, addr += PAGE_SIZE) { >> + if (!pte_present(*pte)) { >> + swp_entry_t vrange_entry = pte_to_swp_entry(*pte); >> + >> + if (unlikely(is_vpurged_entry(vrange_entry))) { >> + vw->page_was_purged = 1; >> + break; > > This function only detect there is vpurge entry or not. But > VRANGE_NONVOLATILE should remove all vpurge entries. > Otherwise, non-volatiled range still makes SIGBUS. So in the following patch (3/5), we only SIGBUS if the swap entry is_vpurged_entry() && the vma is still marked volatile, so this shouldn't be an issue. thanks -john -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
On Sun, Mar 23, 2014 at 1:26 PM, John Stultz <john.stultz@linaro.org> wrote: > On Sun, Mar 23, 2014 at 10:50 AM, KOSAKI Motohiro > <kosaki.motohiro@gmail.com> wrote: >>> +/** >>> + * vrange_check_purged_pte - Checks ptes for purged pages >>> + * >>> + * Iterates over the ptes in the pmd checking if they have >>> + * purged swap entries. >>> + * >>> + * Sets the vrange_walker.pages_purged to 1 if any were purged. >>> + */ >>> +static int vrange_check_purged_pte(pmd_t *pmd, unsigned long addr, >>> + unsigned long end, struct mm_walk *walk) >>> +{ >>> + struct vrange_walker *vw = walk->private; >>> + pte_t *pte; >>> + spinlock_t *ptl; >>> + >>> + if (pmd_trans_huge(*pmd)) >>> + return 0; >>> + if (pmd_trans_unstable(pmd)) >>> + return 0; >>> + >>> + pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl); >>> + for (; addr != end; pte++, addr += PAGE_SIZE) { >>> + if (!pte_present(*pte)) { >>> + swp_entry_t vrange_entry = pte_to_swp_entry(*pte); >>> + >>> + if (unlikely(is_vpurged_entry(vrange_entry))) { >>> + vw->page_was_purged = 1; >>> + break; >> >> This function only detect there is vpurge entry or not. But >> VRANGE_NONVOLATILE should remove all vpurge entries. >> Otherwise, non-volatiled range still makes SIGBUS. > > So in the following patch (3/5), we only SIGBUS if the swap entry > is_vpurged_entry() && the vma is still marked volatile, so this > shouldn't be an issue. When VOLATILE -> NON-VOLATILE -> VOLATILE transition happen, the page immediately marked "was purged"? I don't understand why vma check help. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
On 03/23/2014 02:50 PM, KOSAKI Motohiro wrote: > On Sun, Mar 23, 2014 at 1:26 PM, John Stultz <john.stultz@linaro.org> wrote: >> On Sun, Mar 23, 2014 at 10:50 AM, KOSAKI Motohiro >> <kosaki.motohiro@gmail.com> wrote: >>>> +/** >>>> + * vrange_check_purged_pte - Checks ptes for purged pages >>>> + * >>>> + * Iterates over the ptes in the pmd checking if they have >>>> + * purged swap entries. >>>> + * >>>> + * Sets the vrange_walker.pages_purged to 1 if any were purged. >>>> + */ >>>> +static int vrange_check_purged_pte(pmd_t *pmd, unsigned long addr, >>>> + unsigned long end, struct mm_walk *walk) >>>> +{ >>>> + struct vrange_walker *vw = walk->private; >>>> + pte_t *pte; >>>> + spinlock_t *ptl; >>>> + >>>> + if (pmd_trans_huge(*pmd)) >>>> + return 0; >>>> + if (pmd_trans_unstable(pmd)) >>>> + return 0; >>>> + >>>> + pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl); >>>> + for (; addr != end; pte++, addr += PAGE_SIZE) { >>>> + if (!pte_present(*pte)) { >>>> + swp_entry_t vrange_entry = pte_to_swp_entry(*pte); >>>> + >>>> + if (unlikely(is_vpurged_entry(vrange_entry))) { >>>> + vw->page_was_purged = 1; >>>> + break; >>> This function only detect there is vpurge entry or not. But >>> VRANGE_NONVOLATILE should remove all vpurge entries. >>> Otherwise, non-volatiled range still makes SIGBUS. >> So in the following patch (3/5), we only SIGBUS if the swap entry >> is_vpurged_entry() && the vma is still marked volatile, so this >> shouldn't be an issue. > When VOLATILE -> NON-VOLATILE -> VOLATILE transition happen, > the page immediately marked "was purged"? > > I don't understand why vma check help. Ok, you have a good point here. I've changed the code in my tree to traverse all the ptes being unmarked and zap any psudo swp entries. This is more expensive, but does provide simpler semantics for these corner cases. Thanks again for the great review! -john -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
diff --git a/include/linux/swap.h b/include/linux/swap.h index 46ba0c6..18c12f9 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -70,8 +70,19 @@ static inline int current_is_kswapd(void) #define SWP_HWPOISON_NUM 0 #endif -#define MAX_SWAPFILES \ - ((1 << MAX_SWAPFILES_SHIFT) - SWP_MIGRATION_NUM - SWP_HWPOISON_NUM) + +/* + * Purged volatile range pages + */ +#define SWP_VRANGE_PURGED_NUM 1 +#define SWP_VRANGE_PURGED (MAX_SWAPFILES + SWP_HWPOISON_NUM + SWP_MIGRATION_NUM) + + +#define MAX_SWAPFILES ((1 << MAX_SWAPFILES_SHIFT) \ + - SWP_MIGRATION_NUM \ + - SWP_HWPOISON_NUM \ + - SWP_VRANGE_PURGED_NUM \ + ) /* * Magic header for a swap area. The first part of the union is diff --git a/include/linux/swapops.h b/include/linux/swapops.h index c0f7526..84f43d9 100644 --- a/include/linux/swapops.h +++ b/include/linux/swapops.h @@ -161,6 +161,16 @@ static inline int is_write_migration_entry(swp_entry_t entry) #endif +static inline swp_entry_t make_vpurged_entry(void) +{ + return swp_entry(SWP_VRANGE_PURGED, 0); +} + +static inline int is_vpurged_entry(swp_entry_t entry) +{ + return swp_type(entry) == SWP_VRANGE_PURGED; +} + #ifdef CONFIG_MEMORY_FAILURE /* * Support for hardware poisoned pages diff --git a/include/linux/vrange.h b/include/linux/vrange.h index 6e5331e..986fa85 100644 --- a/include/linux/vrange.h +++ b/include/linux/vrange.h @@ -1,6 +1,9 @@ #ifndef _LINUX_VRANGE_H #define _LINUX_VRANGE_H +#include <linux/swap.h> +#include <linux/swapops.h> + #define VRANGE_NONVOLATILE 0 #define VRANGE_VOLATILE 1 #define VRANGE_VALID_FLAGS (0) /* Don't yet support any flags */ diff --git a/mm/vrange.c b/mm/vrange.c index 2f8e2ce..1ff3cbd 100644 --- a/mm/vrange.c +++ b/mm/vrange.c @@ -8,6 +8,76 @@ #include <linux/mm_inline.h> #include "internal.h" +struct vrange_walker { + struct vm_area_struct *vma; + int page_was_purged; +}; + + +/** + * vrange_check_purged_pte - Checks ptes for purged pages + * + * Iterates over the ptes in the pmd checking if they have + * purged swap entries. + * + * Sets the vrange_walker.pages_purged to 1 if any were purged. + */ +static int vrange_check_purged_pte(pmd_t *pmd, unsigned long addr, + unsigned long end, struct mm_walk *walk) +{ + struct vrange_walker *vw = walk->private; + pte_t *pte; + spinlock_t *ptl; + + if (pmd_trans_huge(*pmd)) + return 0; + if (pmd_trans_unstable(pmd)) + return 0; + + pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl); + for (; addr != end; pte++, addr += PAGE_SIZE) { + if (!pte_present(*pte)) { + swp_entry_t vrange_entry = pte_to_swp_entry(*pte); + + if (unlikely(is_vpurged_entry(vrange_entry))) { + vw->page_was_purged = 1; + break; + } + } + } + pte_unmap_unlock(pte - 1, ptl); + cond_resched(); + + return 0; +} + + +/** + * vrange_check_purged - Sets up a mm_walk to check for purged pages + * + * Sets up and calls wa_page_range() to check for purge pages. + * + * Returns 1 if pages in the range were purged, 0 otherwise. + */ +static int vrange_check_purged(struct mm_struct *mm, + struct vm_area_struct *vma, + unsigned long start, + unsigned long end) +{ + struct vrange_walker vw; + struct mm_walk vrange_walk = { + .pmd_entry = vrange_check_purged_pte, + .mm = vma->vm_mm, + .private = &vw, + }; + vw.page_was_purged = 0; + vw.vma = vma; + + walk_page_range(start, end, &vrange_walk); + + return vw.page_was_purged; + +} /** * do_vrange - Marks or clears VMAs in the range (start-end) as VM_VOLATILE @@ -106,6 +176,11 @@ success: vma = prev->vm_next; } out: + if (count && (mode == VRANGE_NONVOLATILE)) + *purged = vrange_check_purged(mm, vma, + orig_start, + orig_start+count); + up_read(&mm->mmap_sem); /* report bytes successfully marked, even if we're exiting on error */
Users of volatile ranges will need to know if memory was discarded. This patch adds the purged state tracking required to inform userland when it marks memory as non-volatile that some memory in that range was purged and needs to be regenerated. This simplified implementation which uses some of the logic from Minchan's earlier efforts, so credit to Minchan for his work. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Android Kernel Team <kernel-team@android.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Robert Love <rlove@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave@sr71.net> Cc: Rik van Riel <riel@redhat.com> Cc: Dmitry Adamushko <dmitry.adamushko@gmail.com> Cc: Neil Brown <neilb@suse.de> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Mike Hommey <mh@glandium.org> Cc: Taras Glek <tglek@mozilla.com> Cc: Jan Kara <jack@suse.cz> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> Cc: Michel Lespinasse <walken@google.com> Cc: Minchan Kim <minchan@kernel.org> Cc: linux-mm@kvack.org <linux-mm@kvack.org> Signed-off-by: John Stultz <john.stultz@linaro.org> --- include/linux/swap.h | 15 ++++++++-- include/linux/swapops.h | 10 +++++++ include/linux/vrange.h | 3 ++ mm/vrange.c | 75 +++++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 101 insertions(+), 2 deletions(-)