On Mon, 10 Dec 2012, Linus Torvalds wrote: > [ Adding High Dickins because of the shmem oops. ] I had already noticed, and was about to reply; but only then refreshed my mbox window, to find that you've already done it all for me: thanks. > > On Mon, Dec 10, 2012 at 12:35 PM, Zlatko Calusic > <zlatko.calusic@xxxxxxxx> 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:[<ffffffff81090b9c>] [<ffffffff81090b9c>] 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: [<ffffffff81090e21>] find_lock_page+0x21/0x80 > > Dec 9 21:29:42 titan vmunix: [<ffffffff810a1b60>] shmem_getpage_gfp+0xa0/0x620 > > Dec 9 21:29:42 titan vmunix: [<ffffffff810a224c>] shmem_read_mapping_page_gfp+0x2c/0x50 > > Dec 9 21:29:42 titan vmunix: [<ffffffff812b3611>] i915_gem_object_get_pages_gtt+0xe1/0x270 > > Dec 9 21:29:42 titan vmunix: [<ffffffff812b127f>] i915_gem_object_get_pages+0x4f/0x90 > > Dec 9 21:29:42 titan vmunix: [<ffffffff812b1383>] i915_gem_object_bind_to_gtt+0xc3/0x4c0 > > Dec 9 21:29:42 titan vmunix: [<ffffffff812b4413>] i915_gem_object_pin+0x123/0x190 > > Dec 9 21:29:42 titan vmunix: [<ffffffff812b7d97>] i915_gem_execbuffer_reserve_object.isra.13+0x77/0x190 > > Dec 9 21:29:42 titan vmunix: [<ffffffff812b8171>] i915_gem_execbuffer_reserve.isra.14+0x2c1/0x320 > > Dec 9 21:29:42 titan vmunix: [<ffffffff812b87b2>] i915_gem_do_execbuffer.isra.17+0x5e2/0x11b0 > > Dec 9 21:29:42 titan vmunix: [<ffffffff812b9894>] i915_gem_execbuffer2+0x94/0x280 > > Dec 9 21:29:42 titan vmunix: [<ffffffff81287de3>] drm_ioctl+0x493/0x530 > > Dec 9 21:29:42 titan vmunix: [<ffffffff810d9cbf>] do_vfs_ioctl+0x8f/0x530 > > Dec 9 21:29:42 titan vmunix: [<ffffffff810da1ab>] sys_ioctl+0x4b/0x90 > > Dec 9 21:29:42 titan vmunix: [<ffffffff8154a4d2>] 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. Yes, just what I was about to say; except I never considered the -6. I was going to suggest it's a new notebook with not-so-good memory, but see that Borislav has since made a better suggestion. > > None of it looks all that much related to whether the i915 driver uses > GFP_NO_KSWAPD or not, though. Yes, no evidence here of anything to delay 3.7 further. I'm running on current git, and no problems observed; but then, I never did see any of these kswapd problems anyway. And, in particular, I was unable to reproduce Zlatko's 1GB of 4GB kept free (on yesterday's tree, with no swap) - I saw about 100MB kept free. Hugh -- 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>