LKML Archive on
help / color / mirror / Atom feed
From: Robin Holt <>
To: Rick Jones <>
Cc: Petr Tesarik <>,,,
Subject: Re: [PATCH 0/2] enable irqs when waiting for rwlocks
Date: Thu, 23 Oct 2008 09:12:32 -0500	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <>

On Wed, Oct 22, 2008 at 10:31:53AM -0700, Rick Jones wrote:
> Petr Tesarik wrote:
>> Hello,
>> SGI has observed that on large systems, interrupts are not serviced for
>> a long period of time when waiting for a rwlock. The following patch
>> series re-enables irqs while waiting for the lock, resembling the code
>> which is already there for spinlocks.
> Perhaps I'm just out in left field, but that (and the similar behaviour  
> for obtaining a spinlock?) feels like treating a symptom rather than a  
> root cause where the root cause would appear to be long lock hold  
> times/contention?

Sometimes lock contention on large systems will take a few seconds to
pass.  This is normal behavior which simply can not be eliminated.  For
those cases, we need to rely upon being able to re-enable interrupts and
allowing other operations to continue normally.  Simply put, in some
cases, nothing more can be done.


      reply	other threads:[~2008-10-23 14:12 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-10-22  8:33 Petr Tesarik
2008-10-22  8:34 ` [PATCH 1/2] Allow rwlocks to re-enable interrupts Petr Tesarik
2008-10-22  8:45   ` Peter Zijlstra
2008-10-22  8:58     ` Petr Tesarik
2008-10-22 17:24       ` Peter Zijlstra
2008-10-22 19:05         ` Matthew Wilcox
2008-10-22 19:19           ` Peter Zijlstra
2008-10-22 17:31 ` [PATCH 0/2] enable irqs when waiting for rwlocks Rick Jones
2008-10-23 14:12   ` Robin Holt [this message]

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:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \ \ \ \ \ \ \ \
    --subject='Re: [PATCH 0/2] enable irqs when waiting for rwlocks' \

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).