From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
To: cl@linux.com
Cc: glommer@parallels.com, penberg@kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [linux-next-20130422] Bug in SLAB?
Date: Fri, 10 May 2013 21:38:47 +0900 [thread overview]
Message-ID: <201305102138.BDF90621.LFFOFtHSQOMVOJ@I-love.SAKURA.ne.jp> (raw)
In-Reply-To: <201305100654.FCI28926.HOtMVOJLFFFSQO@I-love.SAKURA.ne.jp>
Tetsuo Handa wrote:
> Can we manage with allocating only 26 elements when MAX_ORDER + PAGE_SHIFT > 26
> (e.g. PAGE_SIZE == 256 * 1024) ?
>
> Can kmalloc_index()/kmalloc_size()/kmalloc_slab() etc. work correctly when
> MAX_ORDER + PAGE_SHIFT > 26 (e.g. PAGE_SIZE == 256 * 1024) ?
>
Today I compared SLAB/SLUB code. If I understood correctly, the line
if (size <= 64 * 1024 * 1024) return 26;
in kmalloc_index() is redundant (in fact, kmalloc_caches[26] is out of range)
and conflicts with what the comment
* The largest kmalloc size supported by the SLAB allocators is
* 32 megabyte (2^25) or the maximum allocatable page order if that is
* less than 32 MB.
says, and 0 <= kmalloc_index() <= 25 is always true for SLAB and
0 <= kmalloc_index() <= PAGE_SHIFT+1 is always true for SLUB.
Therefore, towards 3.10-rc1,
> > - for (i = 1; i < PAGE_SHIFT + MAX_ORDER; i++) {
> > + for (i = 1; i =< KMALLOC_SHIFT_HIGH; i++) {
>
-+ for (i = 1; i =< KMALLOC_SHIFT_HIGH; i++) {
++ for (i = 1; i <= KMALLOC_SHIFT_HIGH; i++) {
would be the last fix for me. (I don't know why kmalloc_caches[0] is excluded.)
next prev parent reply other threads:[~2013-05-10 12:38 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 [this message]
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
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
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