[Sorry for top-post but...] This patch still isn't upstream. Who should be shepherding it to Linus? Without it we're seeing crashes on Fedora when running regression tests that use dm-raid (dm target that wraps MD raid), e.g.: 6,484484,682379136295,-;md: mdX: recovery done. 6,484485,682379145308,-;bio: create slab <bio-0> at 0 6,484486,682379147581,-;md/raid:mdX: device dm-17 operational as raid disk 4 6,484487,682379149216,-;md/raid:mdX: device dm-11 operational as raid disk 2 6,484488,682379150829,-;md/raid:mdX: device dm-20 operational as raid disk 1 6,484489,682379152369,-;md/raid:mdX: device dm-9 operational as raid disk 0 3,484490,682379153954,-;kmem_cache_sanity_check (raid6-ffff880014e8b010): Cache name already exists. 4,484491,682379155824,-;CPU: 0 PID: 11228 Comm: lvm Not tainted 3.14.0-0.rc6.git0.1.fc21.x86_64 #1 4,484492,682379157704,-;Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2007 4,484493,682379159298,-; 0000000000000000 00000000a0bb80c5 ffff88003428d9d8 ffffffff816edd6b 4,484494,682379161238,-; ffff880076b51700 ffff88003428da50 ffffffff811982c3 0000000000000000 4,484495,682379163199,-; 0000000000000000 0000000000000790 0000000000000000 0000000000000000 4,484496,682379165206,-;Call Trace: 4,484497,682379166523,-; [<ffffffff816edd6b>] dump_stack+0x45/0x56 4,484498,682379168098,-; [<ffffffff811982c3>] kmem_cache_create_memcg+0x143/0x3e0 4,484499,682379169854,-; [<ffffffff8119858b>] kmem_cache_create+0x2b/0x30 4,484500,682379171541,-; [<ffffffffa020fc6c>] setup_conf+0x5cc/0x810 [raid456] 4,484501,682379173264,-; [<ffffffff811771ad>] ? mempool_create_node+0xdd/0x140 4,484502,682379174988,-; [<ffffffff81176dd0>] ? mempool_alloc_slab+0x20/0x20 4,484503,682379176728,-; [<ffffffffa0210a38>] run+0x868/0xa60 [raid456] 4,484504,682379178380,-; [<ffffffff81220a3e>] ? bioset_create+0x21e/0x2e0 4,484505,682379180038,-; [<ffffffff81563d3a>] md_run+0x3fa/0x980 4,484506,682379181631,-; [<ffffffff81221778>] ? bio_put+0x78/0x90 4,484507,682379183339,-; [<ffffffff8155badd>] ? sync_page_io+0x8d/0x110 4,484508,682379185000,-; [<ffffffffa0227570>] raid_ctr+0xf30/0x1389 [dm_raid] 4,484509,682379186771,-; [<ffffffff8156f857>] dm_table_add_target+0x177/0x460 4,484510,682379188538,-; [<ffffffff81572d57>] table_load+0x157/0x380 4,484511,682379190198,-; [<ffffffff81572c00>] ? retrieve_status+0x1c0/0x1c0 4,484512,682379191925,-; [<ffffffff815739c5>] ctl_ioctl+0x255/0x500 4,484513,682379193589,-; [<ffffffff811e8b00>] ? do_sync_write+0x50/0xa0 4,484514,682379195256,-; [<ffffffff81573c83>] dm_ctl_ioctl+0x13/0x20 4,484515,682379196900,-; [<ffffffff811fc790>] do_vfs_ioctl+0x2e0/0x4a0 4,484516,682379198600,-; [<ffffffff811eb931>] ? __sb_end_write+0x31/0x60 4,484517,682379200286,-; [<ffffffff811e9392>] ? vfs_write+0x172/0x1e0 4,484518,682379201957,-; [<ffffffff811fc9f1>] SyS_ioctl+0xa1/0xc0 4,484519,682379203651,-; [<ffffffff816fe129>] system_call_fastpath+0x16/0x1b 3,484520,682379205496,-;md/raid:mdX: couldn't allocate 0kB for buffers On Tue, Mar 04 2014 at 5:13pm -0500, Mikulas Patocka <mpatocka@xxxxxxxxxx> wrote: > The patch 3e374919b314f20e2a04f641ebc1093d758f66a4 is supposed to fix the > problem where kmem_cache_create incorrectly reports duplicate cache name > and fails. The problem is described in the header of that patch. > > However, the patch doesn't really fix the problem because of these > reasons: > > * the logic to test for debugging is reversed. It was intended to perform > the check only if slub debugging is enabled (which implies that caches > with the same parameters are not merged). Therefore, there should be > #if !defined(CONFIG_SLUB) || defined(CONFIG_SLUB_DEBUG_ON) > The current code has the condition reversed and performs the test if > debugging is disabled. > > * slub debugging may be enabled or disabled based on kernel command line, > CONFIG_SLUB_DEBUG_ON is just the default settings. Therefore the test > based on definition of CONFIG_SLUB_DEBUG_ON is unreliable. > > This patch fixes the problem by removing the test > "!defined(CONFIG_SLUB_DEBUG_ON)". Therefore, duplicate names are never > checked if the SLUB allocator is used. > > Note to stable kernel maintainers: when backporint this patch, please > backport also the patch 3e374919b314f20e2a04f641ebc1093d758f66a4. > > Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx> > Cc: stable@xxxxxxxxxxxxxxx # 3.6+ > > --- > mm/slab_common.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > Index: linux-3.14-rc5/mm/slab_common.c > =================================================================== > --- linux-3.14-rc5.orig/mm/slab_common.c 2014-03-04 22:47:02.000000000 +0100 > +++ linux-3.14-rc5/mm/slab_common.c 2014-03-04 22:47:08.000000000 +0100 > @@ -56,7 +56,7 @@ static int kmem_cache_sanity_check(struc > continue; > } > > -#if !defined(CONFIG_SLUB) || !defined(CONFIG_SLUB_DEBUG_ON) > +#if !defined(CONFIG_SLUB) > /* > * For simplicity, we won't check this in the list of memcg > * caches. We have control over memcg naming, and if there > > -- > dm-devel mailing list > dm-devel@xxxxxxxxxx > https://www.redhat.com/mailman/listinfo/dm-devel -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>