From: Sergey Senozhatsky <senozhatsky@chromium.org>
To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
John Johansen <john.johansen@canonical.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
Tomasz Figa <tfiga@chromium.org>,
linux-kernel@vger.kernel.org,
linux-security-module@vger.kernel.org
Subject: apparmor: global buffers spin lock may get contended
Date: Tue, 13 Jul 2021 22:19:52 +0900 [thread overview]
Message-ID: <YO2S+C7Cw7AS7bsg@google.com> (raw)
Hi,
We've notices that apparmor has switched from using per-CPU buffer pool
and per-CPU spin_lock to a global spin_lock in df323337e507a0009d3db1ea.
This seems to be causing some contention on our build machines (with
quite a bit of cores). Because that global spin lock is a part of the
stat() sys call (and perhaps some other)
E.g.
- 9.29% 0.00% clang++ [kernel.vmlinux]
- 9.28% entry_SYSCALL_64_after_hwframe
- 8.98% do_syscall_64
- 7.43% __do_sys_newlstat
- 7.43% vfs_statx
- 7.18% security_inode_getattr
- 7.15% apparmor_inode_getattr
- aa_path_perm
- 3.53% aa_get_buffer
- 3.47% _raw_spin_lock
3.44% native_queued_spin_lock_slowpath
- 3.49% aa_put_buffer.part.0
- 3.45% _raw_spin_lock
3.43% native_queued_spin_lock_slowpath
Can we fix this contention?
next reply other threads:[~2021-07-13 13:19 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-13 13:19 Sergey Senozhatsky [this message]
2021-08-15 9:47 ` apparmor: global buffers spin lock may get contended John Johansen
2022-10-28 9:34 ` John Johansen
2022-10-31 3:52 ` Sergey Senozhatsky
2022-10-31 3:55 ` John Johansen
2022-10-31 4:04 ` Sergey Senozhatsky
2023-02-17 0:03 ` John Johansen
2023-02-17 0:08 ` [PATCH v3] " John Johansen
2023-02-17 10:44 ` Sebastian Andrzej Siewior
2023-02-20 8:42 ` John Johansen
2023-02-21 21:27 ` Anil Altinay
2023-06-26 23:35 ` Anil Altinay
[not found] ` <CACCxZWO-+M-J_enENr7q1WDcu1U8vYFoytqJxAh=x-nuP268zA@mail.gmail.com>
2023-06-27 0:31 ` John Johansen
2023-10-06 4:18 ` Sergey Senozhatsky
2023-10-17 9:21 ` [PATCH v5 0/4] apparmor: cache buffers on percpu list if there is lock, contention John Johansen
2023-10-17 9:23 ` [PATCH v5 1/4] " John Johansen
2023-10-17 9:24 ` [PATCH v5 2/4] apparmor: exponential backoff on cache buffer contention John Johansen
2023-10-17 9:25 ` [PATCH v5 3/4] apparmor: experiment with faster backoff on global buffer John Johansen
2023-10-17 9:26 ` [PATCH v5 4/4] apparmor: limit the number of buffers in percpu cache John Johansen
2023-10-26 5:13 ` [PATCH v5 0/4] apparmor: cache buffers on percpu list if there is lock, contention Sergey Senozhatsky
[not found] ` <20221030013028.3557-1-hdanton@sina.com>
2022-10-30 6:32 ` apparmor: global buffers spin lock may get contended John Johansen
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