From: Manfred Spraul <manfred@colorfullife.com>
To: Mike Galbraith <efault@gmx.de>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
paulmck@linux.vnet.ibm.com, Nadia Derbey <Nadia.Derbey@bull.net>,
Andrew Morton <akpm@linux-foundation.org>,
Peter Zijlstra <peterz@infradead.org>,
Pavel Emelianov <xemul@openvz.org>
Subject: Re: Scalability requirements for sysv ipc (+namespaces broken with SEM_UNDO)
Date: Sun, 30 Mar 2008 16:12:18 +0200 [thread overview]
Message-ID: <47EF9FC2.3050901@colorfullife.com> (raw)
In-Reply-To: <1206460206.4414.21.camel@marge.simson.net>
Mike Galbraith wrote:
> On Sat, 2008-03-22 at 20:08 +0100, Manfred Spraul wrote:
>
>
>> just the normal performance of 2.6.25-rc3 is abyssimal, 55 to 60% slower
>> than 2.6.18.8:
>>
>
> After manually reverting 3e148c79938aa39035669c1cfa3ff60722134535,
> 2.6.25.git scaled linearly
We can't just revert that patch: with IDR, a global lock is mandatory :-(
We must either revert the whole idea of using IDR or live with the
reduced scalability.
Actually, there are further bugs: the undo structures are not
namespace-aware, thus semop with SEM_UNDO, unshare, create new array
with same id, but more semaphores, another semop with SEM_UNDO will
corrupt kernel memory :-(
I'll try to clean up the bugs first, then I'll look at the scalability
again.
--
Manfred
next prev parent reply other threads:[~2008-03-30 14:12 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-03-21 9:41 Scalability requirements for sysv ipc (was: ipc: store ipcs into IDRs) Manfred Spraul
2008-03-21 12:45 ` Nadia Derbey
2008-03-21 13:33 ` Scalability requirements for sysv ipc Manfred Spraul
2008-03-21 14:13 ` Paul E. McKenney
2008-03-21 16:08 ` Manfred Spraul
2008-03-22 5:43 ` Mike Galbraith
2008-03-22 10:10 ` Manfred Spraul
2008-03-22 11:53 ` Mike Galbraith
2008-03-22 14:22 ` Manfred Spraul
2008-03-22 19:08 ` Manfred Spraul
2008-03-25 15:50 ` Mike Galbraith
2008-03-25 16:13 ` Peter Zijlstra
2008-03-25 18:31 ` Mike Galbraith
2008-03-26 6:18 ` Mike Galbraith
2008-03-30 14:12 ` Manfred Spraul [this message]
2008-03-30 15:21 ` Scalability requirements for sysv ipc (+namespaces broken with SEM_UNDO) David Newall
2008-03-30 17:18 ` Mike Galbraith
2008-04-04 14:59 ` Nadia Derbey
2008-04-04 15:03 ` Nadia Derbey
2008-03-22 19:35 ` Scalability requirements for sysv ipc Mike Galbraith
2008-03-23 6:38 ` Manfred Spraul
2008-03-23 7:15 ` Mike Galbraith
2008-03-23 7:08 ` Mike Galbraith
2008-03-23 7:20 ` Mike Galbraith
2008-03-27 22:29 ` Bill Davidsen
2008-03-28 9:49 ` Manfred Spraul
2008-03-25 16:00 ` Nadia Derbey
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=47EF9FC2.3050901@colorfullife.com \
--to=manfred@colorfullife.com \
--cc=Nadia.Derbey@bull.net \
--cc=akpm@linux-foundation.org \
--cc=efault@gmx.de \
--cc=linux-kernel@vger.kernel.org \
--cc=paulmck@linux.vnet.ibm.com \
--cc=peterz@infradead.org \
--cc=xemul@openvz.org \
/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.