From: Andi Kleen <ak@muc.de>
To: Arjan van de Ven <arjan@infradead.org>
Cc: David Howells <dhowells@redhat.com>,
Andrew Morton <akpm@osdl.org>,
Badari Pulavarty <pbadari@us.ibm.com>,
linux-aio@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: aio stress panic on 2.6.11-mm1
Date: Wed, 09 Mar 2005 12:17:19 +0100 [thread overview]
Message-ID: <m1k6ohvzk0.fsf@muc.de> (raw)
In-Reply-To: <1110366469.6280.84.camel@laptopd505.fenrus.org> (Arjan van de Ven's message of "Wed, 09 Mar 2005 12:07:48 +0100")
Arjan van de Ven <arjan@infradead.org> writes:
> On Wed, 2005-03-09 at 16:34 +0530, Suparna Bhattacharya wrote:
>> Any sense of how costly it is to use spin_lock_irq's vs spin_lock
>> (across different architectures)
>
> on x86 it makes a difference of maybe a few cycles. At most.
> However please consider using spin_lock_irqsave(); the _irq() variant,
> while it can be used correctly, is a major source of bugs since it
> unconditionally enables interrupts on unlock.
irqsave is much worse than _irq on P4.
However the spinlock already synchronizes the CPU, so some of the
cost should be mitigated.
-Andi
next prev parent reply other threads:[~2005-03-09 11:18 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20050308170107.231a145c.akpm@osdl.org>
[not found] ` <1110327267.24286.139.camel@dyn318077bld.beaverton.ibm.com>
[not found] ` <18744.1110364438@redhat.com>
2005-03-09 11:04 ` aio stress panic on 2.6.11-mm1 Suparna Bhattacharya
2005-03-09 11:05 ` Andrew Morton
2005-03-09 11:07 ` Arjan van de Ven
2005-03-09 11:17 ` Andi Kleen [this message]
2005-03-09 11:28 ` Andrew Morton
2005-03-09 11:59 ` David Howells
2005-03-09 12:12 ` [PATCH] rwsem: Make rwsems use interrupt disabling spinlocks David Howells
2005-03-09 17:35 ` Badari Pulavarty
2005-03-09 19:18 ` Badari Pulavarty
2005-03-09 19:16 ` Badari Pulavarty
2005-03-09 19:42 ` Andrew Morton
2005-03-09 20:10 ` Arjan van de Ven
2005-03-11 9:40 ` Ingo Molnar
2005-03-11 10:07 ` Andrew Morton
2005-03-11 10:25 ` Ingo Molnar
2005-03-09 11:10 ` aio stress panic on 2.6.11-mm1 Arjan van de Ven
2005-03-09 11:21 ` Andi Kleen
2005-03-09 14:48 ` Suparna Bhattacharya
2005-03-09 21:58 ` David Howells
2005-03-09 11:11 ` Andi Kleen
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=m1k6ohvzk0.fsf@muc.de \
--to=ak@muc.de \
--cc=akpm@osdl.org \
--cc=arjan@infradead.org \
--cc=dhowells@redhat.com \
--cc=linux-aio@kvack.org \
--cc=linux-kernel@vger.kernel.org \
--cc=pbadari@us.ibm.com \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.