From: Christoph Lameter <cl@linux.com>
To: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: glommer@parallels.com, penberg@kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [linux-next-20130422] Bug in SLAB?
Date: Tue, 30 Apr 2013 17:27:53 +0000 [thread overview]
Message-ID: <0000013e5bfc7c4d-54fa9464-dccd-4157-b4a5-22594261eaf3-000000@email.amazonses.com> (raw)
In-Reply-To: <201305010101.CGB86424.JFQOtSFOVOLFHM@I-love.SAKURA.ne.jp>
On Wed, 1 May 2013, Tetsuo Handa wrote:
> Christoph Lameter wrote:
> > On Tue, 30 Apr 2013, Tetsuo Handa wrote:
> >
> > > The testcases still trigger BUG() at 32M:
> >
> > I thought we established that MAX_ORDER only allows a maximum of 8M sized
> > allocations? Why are you trying 32M?
>
> Only for regression testing. At least until Linux 3.9, requesting too large
> size didn't trigger oops, did it? I'm not expecting kmalloc() to trigger oops
> for Linux 3.10 and future kernels.
It did for SLUB. SLAB returned NULL for some cases.
> "kmalloc() returning NULL for these allocations" is needed by "try kmalloc()
> first, fallback to vmalloc()" allocation. There are kernel modules which expect
> kmalloc() to return NULL rather than oops when the requested size is larger
> than KMALLOC_MAX_SIZE bytes. If kmalloc() suddenly starts triggering oops, such
> modules will break.
This behavior has been in there for years. Why try a kmalloc that
always fails since the size is too big?
> Anyway, there is a regression we want to fix : we won't be able to boot
> Linux 3.10-rc1 for x86_32 built with CONFIG_DEBUG_SLAB=y &&
> CONFIG_DEBUG_SPINLOCK=y && CONFIG_DEBUG_PAGEALLOC=y .
> ("Fix off by one error in slab.h" did not fix the regression.)
Hmm... Where does this fail? In slab?
next prev parent reply other threads:[~2013-04-30 17:27 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-04-24 12:08 [linux-next-20130422] Bug in bootup code or debug code? Tetsuo Handa
2013-04-25 12:20 ` [linux-next-20130422] Bug in SLAB? Tetsuo Handa
2013-04-29 2:40 ` Tetsuo Handa
2013-04-29 10:12 ` Pekka Enberg
2013-04-29 14:44 ` Glauber Costa
2013-04-29 14:59 ` Christoph Lameter
2013-04-29 15:16 ` Glauber Costa
2013-04-29 15:46 ` Christoph Lameter
2013-04-29 15:54 ` Glauber Costa
2013-04-29 15:28 ` Tetsuo Handa
2013-04-29 16:16 ` Tetsuo Handa
2013-05-09 12:25 ` Tetsuo Handa
2013-05-09 14:14 ` Christoph Lameter
2013-05-09 21:54 ` Tetsuo Handa
2013-05-10 12:38 ` Tetsuo Handa
2013-05-10 15:57 ` Christoph Lameter
[not found] ` <201305272153.HEH51089.OHFQMOOtFLSFVJ@I-love.SAKURA.ne.jp>
2013-06-17 11:59 ` Tetsuo Handa
2013-04-29 17:48 ` Christoph Lameter
2013-04-29 21:45 ` Tetsuo Handa
2013-04-30 14:26 ` Christoph Lameter
2013-04-30 16:01 ` Tetsuo Handa
2013-04-30 17:27 ` Christoph Lameter [this message]
2013-05-01 8:05 ` Pekka Enberg
2013-05-02 15:12 ` Christoph Lameter
2013-05-01 12:14 ` Tetsuo Handa
2013-05-02 11:51 ` Tetsuo Handa
2013-05-02 20:53 ` Christoph Lameter
2013-05-03 8:26 ` Tetsuo Handa
2013-05-03 15:43 ` Christoph Lameter
2013-05-06 6:59 ` Geert Uytterhoeven
2013-05-06 7:27 ` Pekka Enberg
2013-05-03 18:04 ` Christoph Lameter
2013-05-03 18:48 ` Tetsuo Handa
2013-05-03 19:21 ` Christoph Lameter
2013-05-04 0:15 ` Tetsuo Handa
2013-05-06 13:46 ` Christoph Lameter
2013-05-07 10:38 ` Tetsuo Handa
2013-05-07 14:28 ` Christoph Lameter
2013-07-01 20:09 ` Andrew Morton
2013-07-01 21:45 ` Tetsuo Handa
2013-07-01 21:53 ` Andrew Morton
2013-07-02 12:49 ` Tetsuo Handa
2013-07-02 19:12 ` Andrew Morton
2013-07-07 15:58 ` Pekka Enberg
2013-05-06 6:32 ` Pekka Enberg
2013-05-06 13:47 ` Christoph Lameter
2013-05-06 20:24 ` Pekka Enberg
2013-05-07 14:23 ` Christoph Lameter
2013-05-07 14:44 ` Pekka Enberg
2013-05-07 15:40 ` Christoph Lameter
2013-04-30 14:34 ` Christoph Lameter
2013-05-01 8:03 ` Pekka Enberg
2013-05-02 15:13 ` Christoph Lameter
2013-04-30 15:16 ` Fix off by one error in slab.h Christoph Lameter
2013-04-29 2:56 ` [linux-next-20130422] Bug in SLAB? Zhan Jianyu
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=0000013e5bfc7c4d-54fa9464-dccd-4157-b4a5-22594261eaf3-000000@email.amazonses.com \
--to=cl@linux.com \
--cc=glommer@parallels.com \
--cc=linux-kernel@vger.kernel.org \
--cc=penberg@kernel.org \
--cc=penguin-kernel@I-love.SAKURA.ne.jp \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).