From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx166.postini.com [74.125.245.166]) by kanga.kvack.org (Postfix) with SMTP id 9B8BE6B004D for ; Sun, 13 May 2012 02:53:17 -0400 (EDT) Received: by vbbey12 with SMTP id ey12so6360804vbb.14 for ; Sat, 12 May 2012 23:53:16 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: References: <201205111008157652383@gmail.com> Date: Sun, 13 May 2012 09:53:15 +0300 Message-ID: Subject: Re: [PATCH] slub: missing test for partial pages flush work in flush_all From: Gilad Ben-Yossef Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org List-ID: To: Christoph Lameter Cc: majianpeng , linux-mm , Pekka Enberg , linux-kernel@vger.kernel.org, Andrew Morton On Fri, May 11, 2012 at 7:14 PM, Christoph Lameter wrote: > Didn't I already ack this before? > > Acked-by: Christoph Lameter > Yes, you did, but the patch description and title was lacking and Majianpeng kindly fixed it, hence the re-send, I guess. I've added Andrew, since he took my original commit that introduces the bug that this patch by Majianpeng fixes (and also LKML). This fix really needs to get into 3.4, otherwise we'll be breaking slub. What's the best way to go about that? Thanks! Gilad > On Fri, 11 May 2012, majianpeng wrote: > >> Subject: [PATCH] slub: missing test for partial pages flush work in flus= h_all >> >> Find some kernel message like: >> SLUB raid5-md127: kmem_cache_destroy called for cache that still has obj= ects. >> Pid: 6143, comm: mdadm Tainted: G =A0 =A0 =A0 =A0 =A0 O 3.4.0-rc6+ =A0 = =A0 =A0 =A0#75 >> Call Trace: >> [] kmem_cache_destroy+0x328/0x400 >> [] free_conf+0x2d/0xf0 [raid456] >> [] stop+0x41/0x60 [raid456] >> [] md_stop+0x1a/0x60 [md_mod] >> [] do_md_stop+0x74/0x470 [md_mod] >> [] md_ioctl+0xff/0x11f0 [md_mod] >> [] blkdev_ioctl+0xd8/0x7a0 >> [] block_ioctl+0x3b/0x40 >> [] do_vfs_ioctl+0x96/0x560 >> [] sys_ioctl+0x91/0xa0 >> [] system_call_fastpath+0x16/0x1b >> >> Then using kmemleak can found those messages: >> unreferenced object 0xffff8800b6db7380 (size 112): >> =A0 comm "mdadm", pid 5783, jiffies 4294810749 (age 90.589s) >> =A0 hex dump (first 32 bytes): >> =A0 =A0 01 01 db b6 ad 4e ad de ff ff ff ff ff ff ff ff =A0.....N.......= ... >> =A0 =A0 ff ff ff ff ff ff ff ff 98 40 4a 82 ff ff ff ff =A0.........@J..= ... >> =A0 backtrace: >> =A0 =A0 [] kmemleak_alloc+0x21/0x50 >> =A0 =A0 [] kmem_cache_alloc+0xeb/0x1b0 >> =A0 =A0 [] kmem_cache_open+0x2f1/0x430 >> =A0 =A0 [] kmem_cache_create+0x158/0x320 >> =A0 =A0 [] setup_conf+0x649/0x770 [raid456] >> =A0 =A0 [] run+0x68b/0x840 [raid456] >> =A0 =A0 [] md_run+0x529/0x940 [md_mod] >> =A0 =A0 [] do_md_run+0x18/0xc0 [md_mod] >> =A0 =A0 [] md_ioctl+0xba8/0x11f0 [md_mod] >> =A0 =A0 [] blkdev_ioctl+0xd8/0x7a0 >> =A0 =A0 [] block_ioctl+0x3b/0x40 >> =A0 =A0 [] do_vfs_ioctl+0x96/0x560 >> =A0 =A0 [] sys_ioctl+0x91/0xa0 >> =A0 =A0 [] system_call_fastpath+0x16/0x1b >> =A0 =A0 [] 0xffffffffffffffff >> >> This bug introduced by Commit a8364d5555b2030d093cde0f0795.The >> commit did not include checks for per cpu partial pages being present on= a >> cpu. >> >> Signed-off-by: majianpeng >> --- >> =A0mm/slub.c | =A0 =A02 +- >> =A01 files changed, 1 insertions(+), 1 deletions(-) >> >> diff --git a/mm/slub.c b/mm/slub.c >> index ffe13fd..6fce08f 100644 >> --- a/mm/slub.c >> +++ b/mm/slub.c >> @@ -2040,7 +2040,7 @@ static bool has_cpu_slab(int cpu, void *info) >> =A0 =A0 =A0 struct kmem_cache *s =3D info; >> =A0 =A0 =A0 struct kmem_cache_cpu *c =3D per_cpu_ptr(s->cpu_slab, cpu); >> >> - =A0 =A0 return !!(c->page); >> + =A0 =A0 return c->page || c->partial; >> =A0} >> >> =A0static void flush_all(struct kmem_cache *s) >> --=20 Gilad Ben-Yossef Chief Coffee Drinker gilad@benyossef.com Israel Cell: +972-52-8260388 US Cell: +1-973-8260388 http://benyossef.com "If you take a class in large-scale robotics, can you end up in a situation where the homework eats your dog?" =A0-- Jean-Baptiste Queru -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org