From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <20061029124655.7014.qmail@web32408.mail.mud.yahoo.com> Date: Sun, 29 Oct 2006 04:46:55 -0800 (PST) From: Giridhar Pemmasani Subject: Re: Slab panic on 2.6.19-rc3-git5 (-git4 was OK) In-Reply-To: <84144f020610282358p6d2db50ybd1cbfa3716c53fb@mail.gmail.com> MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="0-295431475-1162126015=:4410" Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Content-Id: Content-Disposition: inline Return-Path: To: Pekka Enberg , "Martin J. Bligh" Cc: Linux Kernel Mailing List , linux-mm , Andy Whitcroft , Linus Torvalds , pgiri@yahoo.com, Andrew Morton List-ID: --- Pekka Enberg wrote: > Hi, > > On 10/29/06, Martin J. Bligh wrote: > > -git4 was fine. -git5 is broken (on PPC64 blade) > > > > As -rc2-mm2 seemed fine on this box, I'm guessing it's something > > that didn't go via Andrew ;-( Looks like it might be something > > JFS or slab specific. Bigger PPC64 box with different config > > was OK though > > > > Full log is here: http://test.kernel.org/abat/59046/debug/console.log > > Good -git4 run: http://test.kernel.org/abat/58997/debug/console.log > > > > kernel BUG in cache_grow at mm/slab.c:2705! > > cpu 0x1: Vector: 700 (Program Check) at [c0000000fffb7710] > > pc: c0000000000c8ad4: .cache_grow+0x64/0x4f0 > > lr: c0000000000c91a8: .cache_alloc_refill+0x248/0x2cc > > sp: c0000000fffb7990 > > msr: 8000000000021032 > > current = 0xc0000000fffab800 > > paca = 0xc00000000047e780 > > pid = 1, comm = swapper > > kernel BUG in cache_grow at mm/slab.c:2705! > > enter ? for help > > [c0000000fffb7a60] c0000000000c91a8 .cache_alloc_refill+0x248/0x2cc > > [c0000000fffb7b20] c0000000000c9708 .kmem_cache_alloc_node+0xd0/0x10c > > [c0000000fffb7bc0] c0000000000b69cc .__get_vm_area_node+0xcc/0x230 > > [c0000000fffb7c70] c0000000000b7640 .__vmalloc_node+0x60/0xc0 > > [c0000000fffb7d10] c0000000001ad4c8 .txInit+0x2a0/0x3a8 > > [c0000000fffb7e20] c00000000044c1ec .init_jfs_fs+0x78/0x27c > > [c0000000fffb7ec0] c0000000000094c0 .init+0x1f4/0x3e4 > > [c0000000fffb7f90] c000000000027270 .kernel_thread+0x4c/0x68 > > I only skimmed through this briefly but it looks like due to > 52fd24ca1db3a741f144bbc229beefe044202cac __get_vm_area_node is passing > GFP_HIGHMEM to kmem_cache_alloc_node which is a no-no. > I haven't been able to reproduce this, although I understand why it happens: vmalloc allocates memory with GFP_KERNEL | __GFP_HIGHMEM and with git5, the same flags are passed down to cache_alloc_refill, causing the BUG. The following patch against 2.6.19-rc3-git5 (also attached as attachment, as this mailer may mess up inline copying) should fix it. Note that when calling kmalloc_node, I am masking off __GFP_HIGHMEM with GFP_LEVEL_MASK, whereas __vmalloc_area_node does the same with ~(__GFP_HIGHMEM | __GFP_ZERO). IMHO, using GFP_LEVEL_MASK is preferable, but either should fix this problem. Signed-off-by: Giridhar Pemmasani (pgiri@yahoo.com) diff -Naur linux-2.6.19-rc3-git5.orig/mm/vmalloc.c linux-2.6.19-rc3-git5/mm/vmalloc.c --- linux-2.6.19-rc3-git5.orig/mm/vmalloc.c 2006-10-29 07:26:34.000000000 -0500 +++ linux-2.6.19-rc3-git5/mm/vmalloc.c 2006-10-29 07:28:12.000000000 -0500 @@ -182,7 +182,7 @@ addr = ALIGN(start, align); size = PAGE_ALIGN(size); - area = kmalloc_node(sizeof(*area), gfp_mask, node); + area = kmalloc_node(sizeof(*area), gfp_mask & GFP_LEVEL_MASK, node); if (unlikely(!area)) return NULL; ____________________________________________________________________________________ Access over 1 million songs - Yahoo! Music Unlimited (http://music.yahoo.com/unlimited) --0-295431475-1162126015=:4410 Content-Type: text/x-diff; name="__get_vm_area_node-should-mask-off-gfp-highmem.patch" Content-Description: 16165293-__get_vm_area_node-should-mask-off-gfp-highmem.patch Content-Disposition: inline; filename="__get_vm_area_node-should-mask-off-gfp-highmem.patch" diff -Naur linux-2.6.19-rc3-git5.orig/mm/vmalloc.c linux-2.6.19-rc3-git5/mm/vmalloc.c --- linux-2.6.19-rc3-git5.orig/mm/vmalloc.c 2006-10-29 07:26:34.000000000 -0500 +++ linux-2.6.19-rc3-git5/mm/vmalloc.c 2006-10-29 07:28:12.000000000 -0500 @@ -182,7 +182,7 @@ addr = ALIGN(start, align); size = PAGE_ALIGN(size); - area = kmalloc_node(sizeof(*area), gfp_mask, node); + area = kmalloc_node(sizeof(*area), gfp_mask & GFP_LEVEL_MASK, node); if (unlikely(!area)) return NULL; --0-295431475-1162126015=:4410-- -- 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/ . Don't email: email@kvack.org