linux-kernel - Re: [GIT PULL v2] Early SLAB fixes for 2.6.31

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: <20090615064653.GB18390@wotan.suse.de>
Date:	Mon, 15 Jun 2009 08:46:53 +0200
From:	Nick Piggin <npiggin@...e.de>
To:	Benjamin Herrenschmidt <benh@...nel.crashing.org>
Cc:	Christoph Lameter <cl@...ux-foundation.org>,
	Pekka J Enberg <penberg@...helsinki.fi>,
	torvalds@...ux-foundation.org, linux-kernel@...r.kernel.org,
	akpm@...ux-foundation.org, kamezawa.hiroyu@...fujitsu.com,
	lizf@...fujitsu.com, mingo@...e.hu, yinghai@...nel.org
Subject: Re: [GIT PULL v2] Early SLAB fixes for 2.6.31

On Sat, Jun 13, 2009 at 07:46:03AM +1000, Benjamin Herrenschmidt wrote:
> 
> > Adds code to hot code path.
> 
> A single mask which should be mostly in the noise...

Cacheline load. Yes it will be in the noise. Like all other slowdowns
that get merged ;)


> > The allocators mask flags passed to the page allocator through
> > GFP_RECLAIM_MASK|GFP_CONSTRAINT_MASK. This is done outside of the critical
> > code paths.
> > 
> > The might_sleep issues may be fixed by adding another check to
> > __might_sleep().
> 
> That is not enough because slab and slub explicitely re-enable
> interrupts when __GFP_WAIT is set, which is the problem we need to solve
> in the first place, so we need to do the masking there.
> 
> Cheers,
> Ben.
> 
--
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/