linux-kernel - Re: [patch 1/2] fs: mnt_want

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20090403012955.GA23937@wotan.suse.de>
Date:	Fri, 3 Apr 2009 03:29:55 +0200
From:	Nick Piggin <npiggin@...e.de>
To:	Dave Hansen <dave@...ux.vnet.ibm.com>
Cc:	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	linux-fsdevel@...r.kernel.org,
	Andrew Morton <akpm@...ux-foundation.org>
Subject: Re: [patch 1/2] fs: mnt_want_write speedup

On Thu, Apr 02, 2009 at 11:37:20AM -0700, Dave Hansen wrote:
> On Thu, 2009-04-02 at 20:22 +0200, Nick Piggin wrote:
> > On Wed, Mar 18, 2009 at 12:13:43PM -0700, Dave Hansen wrote:
> > > On Thu, 2009-03-12 at 05:13 +0100, Nick Piggin wrote: 
> > > > On Wed, Mar 11, 2009 at 03:11:17PM -0700, Dave Hansen wrote:
> > > > > I'm feeling a bit better about these, although I am still honestly quite
> > > > > afraid of the barriers.  I also didn't like all the #ifdefs much, but
> > > > > here's some help on that.
> > > > 
> > > > FWIW, we have this in suse kernels because page fault performance was
> > > > so bad compared with SLES10. mnt_want_write & co was I think the 2nd
> > > > biggest offender for file backed mappings (after pvops). I think we're
> > > > around parity again even with pvops.
> > > 
> > > Page faults themselves?  Which path was that from?
> > 
> > Yes. file_update_time.
> 
> We should be able to use your mnt_clone_write() optimization separate
> from the mnt_want_write() speedup here, right?  

Yes that should work here.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/