| Message ID | 20190603091008.24776-1-anders.roxell@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | seqlock: mark raw_read_seqcount and read_seqcount_retry as __always_inline | expand |
On Mon, Jun 03, 2019 at 11:10:08AM +0200, Anders Roxell wrote: > If CONFIG_FUNCTION_GRAPH_TRACER is enabled function sched_clock() in > kernel/time/sched_clock.c is marked as notrace. However, functions > raw_read_seqcount and read_seqcount_retry are marked as inline. If > CONFIG_OPTIMIZE_INLINING is set that will make the two functions > tracable which they shouldn't. Might be nice to elaborate a bit here on what goes from specifically for seqlocks. I assume something ends up going recursive thanks to the tracing code? With that: Acked-by: Will Deacon <will.deacon@arm.com> Will
diff --git a/include/linux/seqlock.h b/include/linux/seqlock.h index bcf4cf26b8c8..1b18e3df186e 100644 --- a/include/linux/seqlock.h +++ b/include/linux/seqlock.h @@ -127,7 +127,7 @@ static inline unsigned __read_seqcount_begin(const seqcount_t *s) * seqcount without any lockdep checking and without checking or * masking the LSB. Calling code is responsible for handling that. */ -static inline unsigned raw_read_seqcount(const seqcount_t *s) +static __always_inline unsigned raw_read_seqcount(const seqcount_t *s) { unsigned ret = READ_ONCE(s->sequence); smp_rmb(); @@ -215,7 +215,8 @@ static inline int __read_seqcount_retry(const seqcount_t *s, unsigned start) * If the critical section was invalid, it must be ignored (and typically * retried). */ -static inline int read_seqcount_retry(const seqcount_t *s, unsigned start) +static +__always_inline int read_seqcount_retry(const seqcount_t *s, unsigned start) { smp_rmb(); return __read_seqcount_retry(s, start);
If CONFIG_FUNCTION_GRAPH_TRACER is enabled function sched_clock() in kernel/time/sched_clock.c is marked as notrace. However, functions raw_read_seqcount and read_seqcount_retry are marked as inline. If CONFIG_OPTIMIZE_INLINING is set that will make the two functions tracable which they shouldn't. Rework so that functions raw_read_seqcount and read_seqcount_retry are marked with __always_inline so they will be inlined even if CONFIG_OPTIMIZE_INLINING is turned on. Signed-off-by: Anders Roxell <anders.roxell@linaro.org> --- include/linux/seqlock.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) -- 2.20.1