* [PATCH v2 1/3] scsi: drop unlikely behind BUG_ON() @ 2015-10-05 13:26 Geliang Tang 2015-10-05 13:26 ` [PATCH v2 2/3] sched/core: " Geliang Tang 0 siblings, 1 reply; 5+ messages in thread From: Geliang Tang @ 2015-10-05 13:26 UTC (permalink / raw) To: James E.J. Bottomley; +Cc: Geliang Tang, linux-scsi, linux-kernel (1) For !CONFIG_BUG cases, the bug call is a no-op, so we couldn't care less and the change is ok. (2) ppc and mips, which HAVE_ARCH_BUG_ON, do not rely on branch predictions as it seems to be pointless[1] and thus callers should not be trying to push an optimization in the first place. (3) For CONFIG_BUG and !HAVE_ARCH_BUG_ON cases, BUG_ON() contains an unlikely compiler flag already. Hence, we can drop unlikely behind BUG_ON(). [1] http://lkml.iu.edu/hypermail/linux/kernel/1101.3/02289.html Signed-off-by: Geliang Tang <geliangtang@163.com> Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com> --- Changes in v2: - Just rewrite the commit log. --- drivers/scsi/scsi_lib.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index f570b48..3b5faab 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1164,8 +1164,8 @@ int scsi_init_io(struct scsi_cmnd *cmd) count = blk_rq_map_integrity_sg(rq->q, rq->bio, prot_sdb->table.sgl); - BUG_ON(unlikely(count > ivecs)); - BUG_ON(unlikely(count > queue_max_integrity_segments(rq->q))); + BUG_ON(count > ivecs); + BUG_ON(count > queue_max_integrity_segments(rq->q)); cmd->prot_sdb = prot_sdb; cmd->prot_sdb->table.nents = count; -- 2.5.0 ^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH v2 2/3] sched/core: drop unlikely behind BUG_ON() 2015-10-05 13:26 [PATCH v2 1/3] scsi: drop unlikely behind BUG_ON() Geliang Tang @ 2015-10-05 13:26 ` Geliang Tang 2015-10-05 13:26 ` Geliang Tang 2015-10-06 16:17 ` [tip:sched/core] sched/core: Drop " tip-bot for Geliang Tang 0 siblings, 2 replies; 5+ messages in thread From: Geliang Tang @ 2015-10-05 13:26 UTC (permalink / raw) To: Ingo Molnar, Peter Zijlstra; +Cc: Geliang Tang, linux-kernel (1) For !CONFIG_BUG cases, the bug call is a no-op, so we couldn't care less and the change is ok. (2) ppc and mips, which HAVE_ARCH_BUG_ON, do not rely on branch predictions as it seems to be pointless[1] and thus callers should not be trying to push an optimization in the first place. (3) For CONFIG_BUG and !HAVE_ARCH_BUG_ON cases, BUG_ON() contains an unlikely compiler flag already. Hence, we can drop unlikely behind BUG_ON(). [1] http://lkml.iu.edu/hypermail/linux/kernel/1101.3/02289.html Signed-off-by: Geliang Tang <geliangtang@163.com> --- Changes in v2: - Just rewrite the commit log. --- kernel/sched/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index fe81929..a3518789 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2947,7 +2947,7 @@ static noinline void __schedule_bug(struct task_struct *prev) static inline void schedule_debug(struct task_struct *prev) { #ifdef CONFIG_SCHED_STACK_END_CHECK - BUG_ON(unlikely(task_stack_end_corrupted(prev))); + BUG_ON(task_stack_end_corrupted(prev)); #endif /* * Test if we are atomic. Since do_exit() needs to call into -- 2.5.0 ^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH v2 3/3] mm/nommu: drop unlikely behind BUG_ON() 2015-10-05 13:26 ` [PATCH v2 2/3] sched/core: " Geliang Tang @ 2015-10-05 13:26 ` Geliang Tang 2015-10-06 16:17 ` [tip:sched/core] sched/core: Drop " tip-bot for Geliang Tang 1 sibling, 0 replies; 5+ messages in thread From: Geliang Tang @ 2015-10-05 13:26 UTC (permalink / raw) To: Andrew Morton, Kirill A. Shutemov, Hugh Dickins, Peter Zijlstra (Intel), Andrea Arcangeli, Davidlohr Bueso, Joonsoo Kim, Paul Gortmaker, Leon Romanovsky, Oleg Nesterov Cc: Geliang Tang, linux-mm, linux-kernel (1) For !CONFIG_BUG cases, the bug call is a no-op, so we couldn't care less and the change is ok. (2) ppc and mips, which HAVE_ARCH_BUG_ON, do not rely on branch predictions as it seems to be pointless[1] and thus callers should not be trying to push an optimization in the first place. (3) For CONFIG_BUG and !HAVE_ARCH_BUG_ON cases, BUG_ON() contains an unlikely compiler flag already. Hence, we can drop unlikely behind BUG_ON(). [1] http://lkml.iu.edu/hypermail/linux/kernel/1101.3/02289.html Signed-off-by: Geliang Tang <geliangtang@163.com> Acked-by: Davidlohr Bueso <dave@stgolabs.net> --- Changes in v2: - Just rewrite the commit log. --- mm/nommu.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/mm/nommu.c b/mm/nommu.c index 1e0f168..92be862 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -578,16 +578,16 @@ static noinline void validate_nommu_regions(void) return; last = rb_entry(lastp, struct vm_region, vm_rb); - BUG_ON(unlikely(last->vm_end <= last->vm_start)); - BUG_ON(unlikely(last->vm_top < last->vm_end)); + BUG_ON(last->vm_end <= last->vm_start); + BUG_ON(last->vm_top < last->vm_end); while ((p = rb_next(lastp))) { region = rb_entry(p, struct vm_region, vm_rb); last = rb_entry(lastp, struct vm_region, vm_rb); - BUG_ON(unlikely(region->vm_end <= region->vm_start)); - BUG_ON(unlikely(region->vm_top < region->vm_end)); - BUG_ON(unlikely(region->vm_start < last->vm_top)); + BUG_ON(region->vm_end <= region->vm_start); + BUG_ON(region->vm_top < region->vm_end); + BUG_ON(region->vm_start < last->vm_top); lastp = p; } -- 2.5.0 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH v2 3/3] mm/nommu: drop unlikely behind BUG_ON() @ 2015-10-05 13:26 ` Geliang Tang 0 siblings, 0 replies; 5+ messages in thread From: Geliang Tang @ 2015-10-05 13:26 UTC (permalink / raw) To: Andrew Morton, Kirill A. Shutemov, Hugh Dickins, Peter Zijlstra (Intel), Andrea Arcangeli, Davidlohr Bueso, Joonsoo Kim, Paul Gortmaker, Leon Romanovsky, Oleg Nesterov Cc: Geliang Tang, linux-mm, linux-kernel (1) For !CONFIG_BUG cases, the bug call is a no-op, so we couldn't care less and the change is ok. (2) ppc and mips, which HAVE_ARCH_BUG_ON, do not rely on branch predictions as it seems to be pointless[1] and thus callers should not be trying to push an optimization in the first place. (3) For CONFIG_BUG and !HAVE_ARCH_BUG_ON cases, BUG_ON() contains an unlikely compiler flag already. Hence, we can drop unlikely behind BUG_ON(). [1] http://lkml.iu.edu/hypermail/linux/kernel/1101.3/02289.html Signed-off-by: Geliang Tang <geliangtang@163.com> Acked-by: Davidlohr Bueso <dave@stgolabs.net> --- Changes in v2: - Just rewrite the commit log. --- mm/nommu.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/mm/nommu.c b/mm/nommu.c index 1e0f168..92be862 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -578,16 +578,16 @@ static noinline void validate_nommu_regions(void) return; last = rb_entry(lastp, struct vm_region, vm_rb); - BUG_ON(unlikely(last->vm_end <= last->vm_start)); - BUG_ON(unlikely(last->vm_top < last->vm_end)); + BUG_ON(last->vm_end <= last->vm_start); + BUG_ON(last->vm_top < last->vm_end); while ((p = rb_next(lastp))) { region = rb_entry(p, struct vm_region, vm_rb); last = rb_entry(lastp, struct vm_region, vm_rb); - BUG_ON(unlikely(region->vm_end <= region->vm_start)); - BUG_ON(unlikely(region->vm_top < region->vm_end)); - BUG_ON(unlikely(region->vm_start < last->vm_top)); + BUG_ON(region->vm_end <= region->vm_start); + BUG_ON(region->vm_top < region->vm_end); + BUG_ON(region->vm_start < last->vm_top); lastp = p; } -- 2.5.0 ^ permalink raw reply related [flat|nested] 5+ messages in thread
* [tip:sched/core] sched/core: Drop unlikely behind BUG_ON() 2015-10-05 13:26 ` [PATCH v2 2/3] sched/core: " Geliang Tang 2015-10-05 13:26 ` Geliang Tang @ 2015-10-06 16:17 ` tip-bot for Geliang Tang 1 sibling, 0 replies; 5+ messages in thread From: tip-bot for Geliang Tang @ 2015-10-06 16:17 UTC (permalink / raw) To: linux-tip-commits Cc: efault, peterz, hpa, linux-kernel, torvalds, geliangtang, mingo, tglx Commit-ID: ce03e4137bb22fc560ad7a07cf4138ae2cd59f65 Gitweb: http://git.kernel.org/tip/ce03e4137bb22fc560ad7a07cf4138ae2cd59f65 Author: Geliang Tang <geliangtang@163.com> AuthorDate: Mon, 5 Oct 2015 21:26:05 +0800 Committer: Ingo Molnar <mingo@kernel.org> CommitDate: Tue, 6 Oct 2015 17:08:22 +0200 sched/core: Drop unlikely behind BUG_ON() (1) For !CONFIG_BUG cases, the bug call is a no-op, so we couldn't care less and the change is ok. (2) PPC and MIPS, which HAVE_ARCH_BUG_ON, do not rely on branch predictions as it seems to be pointless [1] and thus callers should not be trying to push an optimization in the first place. (3) For CONFIG_BUG and !HAVE_ARCH_BUG_ON cases, BUG_ON() contains an unlikely compiler flag already. Hence, we can drop unlikely behind BUG_ON(). [1] http://lkml.iu.edu/hypermail/linux/kernel/1101.3/02289.html Signed-off-by: Geliang Tang <geliangtang@163.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/6fa7125979f98bbeac26e268271769b6ca935c8d.1444051018.git.geliangtang@163.com Signed-off-by: Ingo Molnar <mingo@kernel.org> --- kernel/sched/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index fb14a01..a395db1 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2971,7 +2971,7 @@ static noinline void __schedule_bug(struct task_struct *prev) static inline void schedule_debug(struct task_struct *prev) { #ifdef CONFIG_SCHED_STACK_END_CHECK - BUG_ON(unlikely(task_stack_end_corrupted(prev))); + BUG_ON(task_stack_end_corrupted(prev)); #endif if (unlikely(in_atomic_preempt_off())) { ^ permalink raw reply related [flat|nested] 5+ messages in thread
end of thread, other threads:[~2015-10-06 16:18 UTC | newest] Thread overview: 5+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2015-10-05 13:26 [PATCH v2 1/3] scsi: drop unlikely behind BUG_ON() Geliang Tang 2015-10-05 13:26 ` [PATCH v2 2/3] sched/core: " Geliang Tang 2015-10-05 13:26 ` [PATCH v2 3/3] mm/nommu: " Geliang Tang 2015-10-05 13:26 ` Geliang Tang 2015-10-06 16:17 ` [tip:sched/core] sched/core: Drop " tip-bot for Geliang Tang
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