linux-kernel - Re: [GIT PULL] scheduler fixes

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: Windows password security audit tool. GUI, reports in PDF.

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

Message-ID: <20090528121222.GK6920@wotan.suse.de>
Date:	Thu, 28 May 2009 14:12:22 +0200
From:	Nick Piggin <npiggin@...e.de>
To:	Pekka Enberg <penberg@...helsinki.fi>
Cc:	Linus Torvalds <torvalds@...ux-foundation.org>,
	Ingo Molnar <mingo@...e.hu>, Yinghai Lu <yinghai@...nel.org>,
	Rusty Russell <rusty@...tcorp.com.au>,
	"H. Peter Anvin" <hpa@...or.com>, Jeff Garzik <jgarzik@...ox.com>,
	Alexander Viro <viro@....linux.org.uk>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	cl@...ux-foundation.org, mpm@...enic.com
Subject: Re: [GIT PULL] scheduler fixes

On Thu, May 28, 2009 at 03:06:40PM +0300, Pekka Enberg wrote:
> On Tue, 2009-05-26 at 09:38 +0200, Nick Piggin wrote:
> > On Mon, May 25, 2009 at 09:39:08PM +0300, Pekka Enberg wrote:
> > > Linus Torvalds wrote:
> > > >And vfs_caches_init_early() is actually doing some rather strange things, 
> > > >like doing a "alloc_large_system_hash()" but not unconditionally: it does 
> > > >it in the "late" initialization too, if not done early. inode_init_early 
> > > >does soemthing very similar (ie a _conditional_ early init).
> > > >
> > > >So none of this seems to really get a huge advantage from the early init. 
> > > >There seems to be some subtle NUMA issues, but do we really want that? I 
> > > >get the feeling that nobody ever wanted to do it early, and then the NUMA 
> > > >people said "I don't wnt to do this early, but I don't want to touch the 
> > > >non-NUMA case, so I'll do it early for non-numa, and late for numa".
> > > 
> > > SLUB does sysfs setup in kmem_cache_init() and if I saw some oopses if I 
> > > don't call vfs_caches_init_early() first. I didn't look too closely, though.
> > 
> > Did you also test the NUMA/hashdist case? vfs_caches_init_early doesn't
> > do much in that case.
> 
> No, I tested UMA only.
> 
> On Tue, 2009-05-26 at 09:38 +0200, Nick Piggin wrote:
> > I would say it is much more robust to do sysfs setup later if we move
> > the slab setup so early. Probably it is just quite lucky not to explode
> > in the !numa case because the vfs needs quite a bit of setting up...
> 
> That should not be an issue. SLUB already defers sysfs registration
> until slab_sysfs_init() initcall has been run. So my patches have zero
> change in how SLUB interracts with sysfs, actually.

Oh right, I didn't actually look. An initcall should be fine, but
I wonder why it is crashing if you move it before vfs_caches_init_early?
Those just allocate inode and dentry hash tables...

--
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/