From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx183.postini.com [74.125.245.183]) by kanga.kvack.org (Postfix) with SMTP id 2ECC26B006E for ; Mon, 10 Dec 2012 16:29:16 -0500 (EST) Received: by mail-wi0-f181.google.com with SMTP id hm9so1389324wib.8 for ; Mon, 10 Dec 2012 13:29:14 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <50C6477A.4090005@iskon.hr> References: <20121203194208.GZ24381@cmpxchg.org> <20121204214210.GB20253@cmpxchg.org> <20121205030133.GA17438@wolff.to> <20121206173742.GA27297@wolff.to> <50C32D32.6040800@iskon.hr> <50C3AF80.8040700@iskon.hr> <20121210110337.GH1009@suse.de> <20121210163904.GA22101@cmpxchg.org> <20121210180141.GK1009@suse.de> <50C62AE6.3030000@iskon.hr> <50C6477A.4090005@iskon.hr> From: Linus Torvalds Date: Mon, 10 Dec 2012 13:28:54 -0800 Message-ID: Subject: Re: kswapd craziness in 3.7 Content-Type: text/plain; charset=ISO-8859-1 Sender: owner-linux-mm@kvack.org List-ID: To: Zlatko Calusic Cc: Andrew Morton , Mel Gorman , Johannes Weiner , Rik van Riel , linux-mm , Linux Kernel Mailing List , Hugh Dickins [ Adding High Dickins because of the shmem oops. ] On Mon, Dec 10, 2012 at 12:35 PM, Zlatko Calusic wrote: > > And funny thing that you mention i915, because yesterday my daughter managed to lock up our laptop hard (that was a first), and this is what I found in kern.log after restart: > > Dec 9 21:29:42 titan vmunix: general protection fault: 0000 [#1] PREEMPT SMP > Dec 9 21:29:42 titan vmunix: Modules linked in: vboxpci(O) vboxnetadp(O) vboxnetflt(O) vboxdrv(O) [last unloaded: microcode] > Dec 9 21:29:42 titan vmunix: CPU 2 > Dec 9 21:29:42 titan vmunix: Pid: 2523, comm: Xorg Tainted: G O 3.7.0-rc8 #1 Hewlett-Packard HP Pavilion dv7 Notebook PC/144B > Dec 9 21:29:42 titan vmunix: RIP: 0010:[] [] find_get_page+0x3c/0x90 Ho humm.. I'm not convinced this is related. > Dec 9 21:29:42 titan vmunix: Call Trace: > Dec 9 21:29:42 titan vmunix: [] find_lock_page+0x21/0x80 > Dec 9 21:29:42 titan vmunix: [] shmem_getpage_gfp+0xa0/0x620 > Dec 9 21:29:42 titan vmunix: [] shmem_read_mapping_page_gfp+0x2c/0x50 > Dec 9 21:29:42 titan vmunix: [] i915_gem_object_get_pages_gtt+0xe1/0x270 > Dec 9 21:29:42 titan vmunix: [] i915_gem_object_get_pages+0x4f/0x90 > Dec 9 21:29:42 titan vmunix: [] i915_gem_object_bind_to_gtt+0xc3/0x4c0 > Dec 9 21:29:42 titan vmunix: [] i915_gem_object_pin+0x123/0x190 > Dec 9 21:29:42 titan vmunix: [] i915_gem_execbuffer_reserve_object.isra.13+0x77/0x190 > Dec 9 21:29:42 titan vmunix: [] i915_gem_execbuffer_reserve.isra.14+0x2c1/0x320 > Dec 9 21:29:42 titan vmunix: [] i915_gem_do_execbuffer.isra.17+0x5e2/0x11b0 > Dec 9 21:29:42 titan vmunix: [] i915_gem_execbuffer2+0x94/0x280 > Dec 9 21:29:42 titan vmunix: [] drm_ioctl+0x493/0x530 > Dec 9 21:29:42 titan vmunix: [] do_vfs_ioctl+0x8f/0x530 > Dec 9 21:29:42 titan vmunix: [] sys_ioctl+0x4b/0x90 > Dec 9 21:29:42 titan vmunix: [] system_call_fastpath+0x16/0x1b > > It seems that whenever (if ever?) GFP_NO_KSWAPD removal is attempted again, the i915 driver will need to be taken better care of. That decodes to 11: e8 89 b7 15 00 callq 0x15b79f # radix_tree_lookup_slot 16: 48 85 c0 test %rax,%rax 19: 48 89 c6 mov %rax,%rsi 1c: 74 41 je 0x5f 1e: 48 8b 18 mov (%rax),%rbx # 21: 48 85 db test %rbx,%rbx 24: 74 1f je 0x45 26: f6 c3 03 test $0x3,%bl 29: 75 3c jne 0x67 2b:* 8b 53 1c mov 0x1c(%rbx),%edx <-- trapping instruction 2e: 85 d2 test %edx,%edx 30: 74 d9 je 0xb where %rbx is 0x0200000000000000. That looks like it could be a single-bit error, and should have been zero. It's the "atomic_read(&page->counter)" which is part of "page_cache_get_speculative()" as far as I can tell, and it's the "page" pointer that is that odd (non-pointer) value. The fact that %ecx contains the value "-6" makes me wonder if there was a -ENXIO somewhere, though. None of it looks all that much related to whether the i915 driver uses GFP_NO_KSWAPD or not, though. Linus -- 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