linux-kernel - Re: [RFC 2/2] x86_64: expand kernel stack to 16K

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: <CA+55aFwK5PnWonJZUA0O0dZp=k6RL7gRE5rjSTpxwcbS8ydkyQ@mail.gmail.com>
Date:	Wed, 28 May 2014 09:13:51 -0700
From:	Linus Torvalds <torvalds@...ux-foundation.org>
To:	Steven Rostedt <rostedt@...dmis.org>
Cc:	Richard Weinberger <richard.weinberger@...il.com>,
	Minchan Kim <minchan@...nel.org>,
	LKML <linux-kernel@...r.kernel.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	"linux-mm@...ck.org" <linux-mm@...ck.org>,
	"H. Peter Anvin" <hpa@...or.com>, Ingo Molnar <mingo@...nel.org>,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Mel Gorman <mgorman@...e.de>, Rik van Riel <riel@...hat.com>,
	Johannes Weiner <hannes@...xchg.org>,
	Hugh Dickins <hughd@...gle.com>,
	Rusty Russell <rusty@...tcorp.com.au>,
	"Michael S. Tsirkin" <mst@...hat.com>,
	Dave Hansen <dave.hansen@...el.com>
Subject: Re: [RFC 2/2] x86_64: expand kernel stack to 16K

On Wed, May 28, 2014 at 9:08 AM, Steven Rostedt <rostedt@...dmis.org> wrote:
>
> What performance impact are you looking for? Now if the system is short
> on memory, it would probably cause issues in creating tasks.

It doesn't necessarily need to be short on memory, it could just be
fragmented. But a page order of 2 should still be ok'ish.

That said, this is definitely not a rc7 issue. I'd *much* rather
disable swap from direct reclaim, although that kind of patch too
would be a "can Minchan test it, we can put it in the next merge
window and then backport it if we don't have issues".

I see that Johannes already did a patch for that (and this really
_has_ come up before), although I'd skip the WARN_ON_ONCE() part
except for perhaps Minchan testing it.

               Linus
--
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/