From 19d0070a2792181f79df01277fe00b83b9f7eda7 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Tue, 4 Aug 2020 17:01:23 +0200 Subject: timekeeping/vsyscall: Provide vdso_update_begin/end() Architectures can have the requirement to add additional architecture specific data to the VDSO data page which needs to be updated independent of the timekeeper updates. To protect these updates vs. concurrent readers and a conflicting update through timekeeping, provide helper functions to make such updates safe. vdso_update_begin() takes the timekeeper_lock to protect against a potential update from timekeeper code and increments the VDSO sequence count to signal data inconsistency to concurrent readers. vdso_update_end() makes the sequence count even again to signal data consistency and drops the timekeeper lock. [ Sven: Add interrupt disable handling to the functions ] Signed-off-by: Thomas Gleixner Signed-off-by: Sven Schnelle Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/20200804150124.41692-3-svens@linux.ibm.com --- kernel/time/timekeeping.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/time/timekeeping.c') diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 63a632f9896c..4c7212f3c603 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -50,7 +50,7 @@ static struct { .seq = SEQCNT_ZERO(tk_core.seq), }; -static DEFINE_RAW_SPINLOCK(timekeeper_lock); +DEFINE_RAW_SPINLOCK(timekeeper_lock); static struct timekeeper shadow_timekeeper; /** -- cgit v1.2.3 From b0294f30256bb6023b2044fd607855123863d98f Mon Sep 17 00:00:00 2001 From: Randy Dunlap Date: Thu, 6 Aug 2020 20:32:48 -0700 Subject: time: Delete repeated words in comments Drop repeated words in kernel/time/. {when, one, into} Signed-off-by: Randy Dunlap Signed-off-by: Thomas Gleixner Acked-by: John Stultz Link: https://lore.kernel.org/r/20200807033248.8452-1-rdunlap@infradead.org --- kernel/time/timekeeping.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/time/timekeeping.c') diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 4c7212f3c603..35cd10f1143b 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -2001,7 +2001,7 @@ static inline unsigned int accumulate_nsecs_to_secs(struct timekeeper *tk) * logarithmic_accumulation - shifted accumulation of cycles * * This functions accumulates a shifted interval of cycles into - * into a shifted interval nanoseconds. Allows for O(log) accumulation + * a shifted interval nanoseconds. Allows for O(log) accumulation * loop. * * Returns the unconsumed cycles. -- cgit v1.2.3