From: Peter Zijlstra <peterz@infradead.org>
To: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>,
linux-kernel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
Mandeep Singh Baines <msb@google.com>
Subject: Re: [RFC][PATCH 2/2] add a counter for writers spinning on a rwlock
Date: Mon, 26 Jan 2009 14:48:35 +0100 [thread overview]
Message-ID: <1232977715.4863.81.camel@laptop> (raw)
In-Reply-To: <497cd08f.0c11660a.33a7.ffffdf39@mx.google.com>
On Sun, 2009-01-25 at 12:50 -0800, Frederic Weisbecker wrote:
> This patch adds a counter for writers that enter a rwlock slow path.
> For example it can be useful for slow background tasks which perform some jobs
> on the tasklist, such as the hung_task detector (kernel/hung_task.c).
>
> It adds a inc/dec pair on the slow path and 4 bytes for each rwlocks, so the overhead
> is not null.
>
> Only x86 is supported for now, writers_spinning_lock() will return 0 on other archs (which
> is perhaps not a good idea).
>
> Comments?
_why_ ?
next prev parent reply other threads:[~2009-01-26 13:48 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-01-25 20:50 [RFC][PATCH 2/2] add a counter for writers spinning on a rwlock Frederic Weisbecker
2009-01-26 13:32 ` Ingo Molnar
2009-01-26 13:48 ` Peter Zijlstra [this message]
2009-01-26 15:25 ` Frédéric Weisbecker
2009-01-26 15:37 ` Peter Zijlstra
2009-01-26 16:04 ` Frédéric Weisbecker
2009-01-26 17:36 ` Mandeep Baines
2009-01-26 17:41 ` Peter Zijlstra
2009-01-27 0:30 ` [PATCH v4] softlockup: remove hung_task_check_count Mandeep Singh Baines
2009-01-27 9:27 ` Frederic Weisbecker
2009-01-27 13:26 ` Ingo Molnar
2009-01-27 18:48 ` Mandeep Singh Baines
2009-01-28 8:25 ` Peter Zijlstra
2009-01-29 1:42 ` Mandeep Singh Baines
2009-01-30 20:41 ` Mandeep Singh Baines
2009-01-30 20:46 ` [PATCH 1/2] softlockup: convert read_lock in hung_task to rcu_read_lock Mandeep Singh Baines
2009-01-30 20:49 ` [PATCH 2/2] softlockup: check all tasks in hung_task Mandeep Singh Baines
2009-01-31 19:22 ` Peter Zijlstra
2009-02-03 0:05 ` [PATCH 2/2 v2] " Mandeep Singh Baines
2009-02-03 12:23 ` Ingo Molnar
2009-02-03 20:56 ` [PATCH 2/2 v3] " Mandeep Singh Baines
2009-02-04 19:43 ` Ingo Molnar
2009-02-05 4:35 ` [PATCH 2/2 v4] " Mandeep Singh Baines
2009-02-05 14:34 ` Ingo Molnar
2009-02-05 17:48 ` Andrew Morton
2009-02-05 18:07 ` Ingo Molnar
2009-02-05 18:30 ` Andrew Morton
2009-02-05 18:58 ` Ingo Molnar
2009-02-05 18:40 ` Mandeep Singh Baines
2009-02-05 17:56 ` [PATCH] softlockup: convert read_lock in hung_task to rcu_read_lock Mandeep Singh Baines
2009-02-05 18:13 ` Ingo Molnar
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