linux-kernel - Re: [PATCH] mm: Fix boot crash in mm

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: <4DE2EEFB.1080803@jp.fujitsu.com>
Date:	Mon, 30 May 2011 10:12:27 +0900
From:	KOSAKI Motohiro <kosaki.motohiro@...fujitsu.com>
To:	torvalds@...ux-foundation.org
CC:	mingo@...e.hu, akpm@...ux-foundation.org, tglx@...utronix.de,
	linux-kernel@...r.kernel.org, a.p.zijlstra@...llo.nl,
	linux-mm@...ck.org
Subject: Re: [PATCH] mm: Fix boot crash in mm_alloc()

(2011/05/30 3:43), Linus Torvalds wrote:
> On Sun, May 29, 2011 at 10:19 AM, Linus Torvalds
> <torvalds@...ux-foundation.org> wrote:
>>
>> STILL TOTALLY UNTESTED! The fixes were just from eyeballing it a bit
>> more, not from any actual testing.
> 
> Ok, I eyeballed it some more, and tested both the OFFSTACK and ONSTACK
> case, and decided that I had better commit it now rather than wait any
> later since I'll do the -rc1 later today, and will be on an airplane
> most of tomorrow.
> 
> The exact placement of the cpu_vm_mask_var is up for grabs. For
> example, I started thinking that it might be better to put it *after*
> the mm_context_t, since for the non-OFFSTACK case it's generally
> touched at the beginning rather than the end.
> 
> And the actual change to make the mm_cachep kmem_cache_create() use a
> variable-sized allocation for the OFFSTACK case is similarly left as
> an exercise for the the reader. So effectively, this reverts a lot of
> de03c72cfce5, but does so in a way that should make very it easy to
> get back to where KOSAKI was aiming for.
> 
> Whatever. I was hoping to get comments on it, but I think I need to
> rather push it out to get tested and public than wait any longer. The
> patch *looks* fine, tests ok on my machine, and removes more lines
> than it adds despite the new big comment.

Hi

Thank you Linus and I'm sorry for bother you and guys. So, if I understand
this thread correctly, rest my homework is 1) make cpumask_allocation variable
size 2) remove NR_CPUS bit fill/copy from fork/exec path. Right?

I think (2) is big matter than (1). NR_CPUS(=4096) bits copy easily screw up
cache behavior. Anyway, will do. Thank you!



--
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/