From: Byungchul Park <byungchul@sk.com>
To: linux-kernel@vger.kernel.org
Cc: kernel_team@skhynix.com, torvalds@linux-foundation.org,
damien.lemoal@opensource.wdc.com, linux-ide@vger.kernel.org,
adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org,
mingo@redhat.com, peterz@infradead.org, will@kernel.org,
tglx@linutronix.de, rostedt@goodmis.org, joel@joelfernandes.org,
sashal@kernel.org, daniel.vetter@ffwll.ch, duyuyang@gmail.com,
johannes.berg@intel.com, tj@kernel.org, tytso@mit.edu,
willy@infradead.org, david@fromorbit.com, amir73il@gmail.com,
gregkh@linuxfoundation.org, kernel-team@lge.com,
linux-mm@kvack.org, akpm@linux-foundation.org, mhocko@kernel.org,
minchan@kernel.org, hannes@cmpxchg.org, vdavydov.dev@gmail.com,
sj@kernel.org, jglisse@redhat.com, dennis@kernel.org,
cl@linux.com, penberg@kernel.org, rientjes@google.com,
vbabka@suse.cz, ngupta@vflare.org, linux-block@vger.kernel.org,
josef@toxicpanda.com, linux-fsdevel@vger.kernel.org,
jack@suse.cz, jlayton@kernel.org, dan.j.williams@intel.com,
hch@infradead.org, djwong@kernel.org,
dri-devel@lists.freedesktop.org, rodrigosiqueiramelo@gmail.com,
melissa.srw@gmail.com, hamohammed.sa@gmail.com,
42.hyeyoo@gmail.com, chris.p.wilson@intel.com,
gwan-gyeong.mun@intel.com, max.byungchul.park@gmail.com,
boqun.feng@gmail.com, longman@redhat.com, hdanton@sina.com,
her0gyugyu@gmail.com
Subject: [PATCH v14 25/28] cpu/hotplug: Use a weaker annotation in AP thread
Date: Wed, 8 May 2024 18:47:22 +0900 [thread overview]
Message-ID: <20240508094726.35754-26-byungchul@sk.com> (raw)
In-Reply-To: <20240508094726.35754-1-byungchul@sk.com>
cb92173d1f0 ("locking/lockdep, cpu/hotplug: Annotate AP thread") was
introduced to make lockdep_assert_cpus_held() work in AP thread.
However, the annotation is too strong for that purpose. We don't have to
use more than try lock annotation for that.
rwsem_acquire() implies:
1. might be a waiter on contention of the lock.
2. enter to the critical section of the lock.
All we need in here is to act 2, not 1. So trylock version of annotation
is sufficient for that purpose. Now that dept partially relies on
lockdep annotaions, dept interpets rwsem_acquire() as a potential wait
and might report a deadlock by the wait. So replaced it with trylock
version of annotation.
Signed-off-by: Byungchul Park <byungchul@sk.com>
---
kernel/cpu.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 63447eb85dab..da969f7269b5 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -534,7 +534,7 @@ int lockdep_is_cpus_held(void)
static void lockdep_acquire_cpus_lock(void)
{
- rwsem_acquire(&cpu_hotplug_lock.dep_map, 0, 0, _THIS_IP_);
+ rwsem_acquire(&cpu_hotplug_lock.dep_map, 0, 1, _THIS_IP_);
}
static void lockdep_release_cpus_lock(void)
--
2.17.1
next prev parent reply other threads:[~2024-05-08 10:03 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-08 9:46 [PATCH v14 00/28] DEPT(Dependency Tracker) Byungchul Park
2024-05-08 9:46 ` [PATCH v14 01/28] llist: Move llist_{head, node} definition to types.h Byungchul Park
2024-05-08 9:46 ` [PATCH v14 02/28] dept: Implement Dept(Dependency Tracker) Byungchul Park
2024-05-08 9:47 ` [PATCH v14 03/28] dept: Add single event dependency tracker APIs Byungchul Park
2024-05-08 9:47 ` [PATCH v14 04/28] dept: Add lock " Byungchul Park
2024-05-08 9:47 ` [PATCH v14 05/28] dept: Tie to Lockdep and IRQ tracing Byungchul Park
2024-05-08 9:47 ` [PATCH v14 06/28] dept: Add proc knobs to show stats and dependency graph Byungchul Park
2024-05-08 9:47 ` [PATCH v14 07/28] dept: Distinguish each syscall context from another Byungchul Park
2024-05-08 9:47 ` [PATCH v14 08/28] dept: Distinguish each work " Byungchul Park
2024-05-08 9:47 ` [PATCH v14 09/28] dept: Add a mechanism to refill the internal memory pools on running out Byungchul Park
2024-05-08 9:47 ` [PATCH v14 10/28] dept: Record the latest one out of consecutive waits of the same class Byungchul Park
2024-05-08 9:47 ` [PATCH v14 11/28] dept: Apply sdt_might_sleep_{start, end}() to wait_for_completion()/complete() Byungchul Park
2024-05-08 9:47 ` [PATCH v14 12/28] dept: Apply sdt_might_sleep_{start,end}() to swait Byungchul Park
2024-05-08 9:47 ` [PATCH v14 13/28] dept: Apply sdt_might_sleep_{start, end}() to waitqueue wait Byungchul Park
2024-05-08 9:47 ` [PATCH v14 14/28] dept: Apply sdt_might_sleep_{start, end}() to hashed-waitqueue wait Byungchul Park
2024-05-08 9:47 ` [PATCH v14 15/28] dept: Apply sdt_might_sleep_{start, end}() to dma fence wait Byungchul Park
2024-05-08 9:47 ` [PATCH v14 16/28] dept: Track timeout waits separately with a new Kconfig Byungchul Park
2024-05-08 9:47 ` [PATCH v14 17/28] dept: Apply timeout consideration to wait_for_completion()/complete() Byungchul Park
2024-05-08 9:47 ` [PATCH v14 18/28] dept: Apply timeout consideration to swait Byungchul Park
2024-05-08 9:47 ` [PATCH v14 19/28] dept: Apply timeout consideration to waitqueue wait Byungchul Park
2024-05-08 9:47 ` [PATCH v14 20/28] dept: Apply timeout consideration to hashed-waitqueue wait Byungchul Park
2024-05-08 9:47 ` [PATCH v14 21/28] dept: Apply timeout consideration to dma fence wait Byungchul Park
2024-05-08 9:47 ` [PATCH v14 22/28] dept: Make Dept able to work with an external wgen Byungchul Park
2024-05-08 9:47 ` [PATCH v14 23/28] dept: Track PG_locked with dept Byungchul Park
2024-05-08 9:47 ` [PATCH v14 24/28] dept: Print event context requestor's stacktrace on report Byungchul Park
2024-05-08 9:47 ` Byungchul Park [this message]
2024-05-08 9:47 ` [PATCH v14 26/28] fs/jbd2: Use a weaker annotation in journal handling Byungchul Park
2024-05-08 9:47 ` [PATCH v14 27/28] dept: Add documentation for Dept Byungchul Park
2024-05-08 9:47 ` [PATCH v14 28/28] dept: Add documentation for Dept's APIs Byungchul Park
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20240508094726.35754-26-byungchul@sk.com \
--to=byungchul@sk.com \
--cc=42.hyeyoo@gmail.com \
--cc=adilger.kernel@dilger.ca \
--cc=akpm@linux-foundation.org \
--cc=amir73il@gmail.com \
--cc=boqun.feng@gmail.com \
--cc=chris.p.wilson@intel.com \
--cc=cl@linux.com \
--cc=damien.lemoal@opensource.wdc.com \
--cc=dan.j.williams@intel.com \
--cc=daniel.vetter@ffwll.ch \
--cc=david@fromorbit.com \
--cc=dennis@kernel.org \
--cc=djwong@kernel.org \
--cc=dri-devel@lists.freedesktop.org \
--cc=duyuyang@gmail.com \
--cc=gregkh@linuxfoundation.org \
--cc=gwan-gyeong.mun@intel.com \
--cc=hamohammed.sa@gmail.com \
--cc=hannes@cmpxchg.org \
--cc=hch@infradead.org \
--cc=hdanton@sina.com \
--cc=her0gyugyu@gmail.com \
--cc=jack@suse.cz \
--cc=jglisse@redhat.com \
--cc=jlayton@kernel.org \
--cc=joel@joelfernandes.org \
--cc=johannes.berg@intel.com \
--cc=josef@toxicpanda.com \
--cc=kernel-team@lge.com \
--cc=kernel_team@skhynix.com \
--cc=linux-block@vger.kernel.org \
--cc=linux-ext4@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-ide@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=longman@redhat.com \
--cc=max.byungchul.park@gmail.com \
--cc=melissa.srw@gmail.com \
--cc=mhocko@kernel.org \
--cc=minchan@kernel.org \
--cc=mingo@redhat.com \
--cc=ngupta@vflare.org \
--cc=penberg@kernel.org \
--cc=peterz@infradead.org \
--cc=rientjes@google.com \
--cc=rodrigosiqueiramelo@gmail.com \
--cc=rostedt@goodmis.org \
--cc=sashal@kernel.org \
--cc=sj@kernel.org \
--cc=tglx@linutronix.de \
--cc=tj@kernel.org \
--cc=torvalds@linux-foundation.org \
--cc=tytso@mit.edu \
--cc=vbabka@suse.cz \
--cc=vdavydov.dev@gmail.com \
--cc=will@kernel.org \
--cc=willy@infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).