linux-kernel - [GIT PULL] percpu changes for v5.13-rc4

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Message-ID: <YK//pZfXvXnEFbuT@google.com>
Date:   Thu, 27 May 2021 20:23:01 +0000
From:   Dennis Zhou <dennis@...nel.org>
To:     Linus Torvalds <torvalds@...ux-foundation.org>
Cc:     Tejun Heo <tj@...nel.org>, Christoph Lameter <cl@...ux.com>,
        linux-mm@...ck.org, linux-kernel@...r.kernel.org
Subject: [GIT PULL] percpu changes for v5.13-rc4

Hi Linus,

This contains a cleanup to lib/percpu-refcount.c and an update to the
MAINTAINERS file to more formally take over support for lib/percpu*.

A few things I expect to have ready for-5.14, percpu depopulation
(queued) and an updated to percpu memcg accounting (wip from Roman
Gushchin).

Thanks,
Dennis

The following changes since commit 6efb943b8616ec53a5e444193dccf1af9ad627b5:

  Linux 5.13-rc1 (2021-05-09 14:17:44 -0700)

are available in the Git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu.git for-5.13-fixes

for you to fetch changes up to c547addba7096debac4f99cdfe869a32a81081e2:

  MAINTAINERS: Add lib/percpu* as part of percpu entry (2021-05-13 04:50:30 +0000)

----------------------------------------------------------------
Nikolay Borisov (2):
      percpu_ref: Don't opencode percpu_ref_is_dying
      MAINTAINERS: Add lib/percpu* as part of percpu entry

 MAINTAINERS           | 2 ++
 lib/percpu-refcount.c | 6 +++---
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/MAINTAINERS b/MAINTAINERS
index bd7aff0c120f..9599e313d7f7 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -14317,10 +14317,12 @@ PER-CPU MEMORY ALLOCATOR
 M:	Dennis Zhou <dennis@...nel.org>
 M:	Tejun Heo <tj@...nel.org>
 M:	Christoph Lameter <cl@...ux.com>
+L:	linux-mm@...ck.org
 S:	Maintained
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu.git
 F:	arch/*/include/asm/percpu.h
 F:	include/linux/percpu*.h
+F:	lib/percpu*.c
 F:	mm/percpu*.c
 
 PER-TASK DELAY ACCOUNTING
diff --git a/lib/percpu-refcount.c b/lib/percpu-refcount.c
index a1071cdefb5a..af9302141bcf 100644
--- a/lib/percpu-refcount.c
+++ b/lib/percpu-refcount.c
@@ -275,7 +275,7 @@ static void __percpu_ref_switch_mode(struct percpu_ref *ref,
 	wait_event_lock_irq(percpu_ref_switch_waitq, !data->confirm_switch,
 			    percpu_ref_switch_lock);
 
-	if (data->force_atomic || (ref->percpu_count_ptr & __PERCPU_REF_DEAD))
+	if (data->force_atomic || percpu_ref_is_dying(ref))
 		__percpu_ref_switch_to_atomic(ref, confirm_switch);
 	else
 		__percpu_ref_switch_to_percpu(ref);
@@ -385,7 +385,7 @@ void percpu_ref_kill_and_confirm(struct percpu_ref *ref,
 
 	spin_lock_irqsave(&percpu_ref_switch_lock, flags);
 
-	WARN_ONCE(ref->percpu_count_ptr & __PERCPU_REF_DEAD,
+	WARN_ONCE(percpu_ref_is_dying(ref),
 		  "%s called more than once on %ps!", __func__,
 		  ref->data->release);
 
@@ -465,7 +465,7 @@ void percpu_ref_resurrect(struct percpu_ref *ref)
 
 	spin_lock_irqsave(&percpu_ref_switch_lock, flags);
 
-	WARN_ON_ONCE(!(ref->percpu_count_ptr & __PERCPU_REF_DEAD));
+	WARN_ON_ONCE(!percpu_ref_is_dying(ref));
 	WARN_ON_ONCE(__ref_is_percpu(ref, &percpu_count));
 
 	ref->percpu_count_ptr &= ~__PERCPU_REF_DEAD;