From: Waiman Long <longman@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>, Will Deacon <will@kernel.org>,
Boqun Feng <boqun.feng@gmail.com>
Cc: linux-kernel@vger.kernel.org, john.p.donnelly@oracle.com,
"Hillf Danton" <hdanton@sina.com>,
"Mukesh Ojha" <quic_mojha@quicinc.com>,
"Ting11 Wang 王婷" <wangting11@xiaomi.com>,
"Waiman Long" <longman@redhat.com>
Subject: [PATCH v2 0/2] locking/rwsem: Fix rwsem waiter optimistic spinning problem with RT tasks
Date: Wed, 12 Oct 2022 09:33:31 -0400 [thread overview]
Message-ID: <20221012133333.1265281-1-longman@redhat.com> (raw)
v2:
- Add an additional patch to limit the # of first waiter optimistic
spinning in the writer slowpath.
It turns out the current waiter optimistic spinning code does not work
that well if we have RT tasks in the mix. This patch series include
two different fixes to resolve those issues.
Waiman Long (2):
locking/rwsem: Prevent non-first waiter from spinning in down_write()
slowpath
locking/rwsem: Limit # of null owner retries for handoff writer
kernel/locking/rwsem.c | 31 ++++++++++++++++++++++++++-----
1 file changed, 26 insertions(+), 5 deletions(-)
--
2.31.1
next reply other threads:[~2022-10-12 13:34 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-12 13:33 Waiman Long [this message]
2022-10-12 13:33 ` [PATCH v2 1/2] locking/rwsem: Prevent non-first waiter from spinning in down_write() slowpath Waiman Long
2022-10-12 14:23 ` Mukesh Ojha
2022-10-13 10:02 ` Peter Zijlstra
2022-10-13 13:33 ` Waiman Long
2022-10-13 15:37 ` Waiman Long
2022-10-12 13:33 ` [PATCH v2 2/2] locking/rwsem: Limit # of null owner retries for handoff writer Waiman Long
2022-10-12 14:38 ` Mukesh Ojha
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