From: Waiman Long <waiman.long@hpe.com>
To: Stas Sergeev <stsp@list.ru>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Ingo Molnar <mingo@kernel.org>, Oleg Nesterov <oleg@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
<linux-kernel@vger.kernel.org>,
Scott J Norton <scott.norton@hpe.com>,
Douglas Hatch <doug.hatch@hpe.com>
Subject: Re: [PATCH v2] signals: Avoid unnecessary taking of sighand->siglock
Date: Mon, 26 Sep 2016 17:24:36 -0400 [thread overview]
Message-ID: <57E99214.3040104@hpe.com> (raw)
In-Reply-To: <a0233360-919e-4587-1c56-84b944cd6779@list.ru>
On 09/23/2016 03:43 PM, Stas Sergeev wrote:
> 23.09.2016 19:56, Waiman Long пишет:
>> When running certain database workload on a high-end system with many
>> CPUs, it was found that spinlock contention in the sigprocmask syscalls
>> became a significant portion of the overall CPU cycles as shown below.
> Hi, I was recently facing the same problem, and my solution
> was to extract swapcontext() from libtask - it has better semantic
> and does not do sigprocmask. How much you hack sigprocmask,
> it is still faster to just not call it at all.
> Alternatively, perhaps the speed-up can be achieved if the
> current mask is exported to glibc via vdso.
> Just my 2 cents.
The problem was in a third-party software not under our control. I am
just doing my part to try to alleviate the problem from the kernel's
perspective.
Cheers,
Longman
next prev parent reply other threads:[~2016-09-26 21:24 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-23 16:56 [PATCH v2] signals: Avoid unnecessary taking of sighand->siglock Waiman Long
2016-09-23 19:43 ` Stas Sergeev
2016-09-26 21:24 ` Waiman Long [this message]
2016-09-26 16:28 ` Oleg Nesterov
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