On Wed, Jul 29, 2015 at 11:32 AM, Ming Lei <ming....@canonical.com> wrote: > On Wed, Jul 29, 2015 at 9:51 AM, Johannes Weiner <han...@cmpxchg.org> wrote: >> On Wed, Jul 29, 2015 at 09:27:16AM -0400, Josh Boyer wrote: >>> Hi All, >>> >>> We've gotten a report[1] that any of the upcoming Fedora 23 install >>> images are all failing on 32-bit VMs/machines. Looking at the first >>> instance of the oops, it seems to be a bad page state where a page is >>> still charged to a group and it is trying to be freed. The oops >>> output is below. >>> >>> Has anyone seen this in their 32-bit testing at all? Thus far nobody >>> can recreate this on a 64-bit machine/VM. >>> >>> josh >>> >>> [1] https://bugzilla.redhat.com/show_bug.cgi?id=1247382 >>> >>> [ 9.026738] systemd[1]: Switching root. >>> [ 9.036467] systemd-journald[149]: Received SIGTERM from PID 1 (systemd). >>> [ 9.082262] BUG: Bad page state in process kworker/u5:1 pfn:372ac >>> [ 9.083989] page:f3d32ae0 count:0 mapcount:0 mapping:f2252178 index:0x16a >>> [ 9.085755] flags: 0x40020021(locked|lru|mappedtodisk) >>> [ 9.087284] page dumped because: page still charged to cgroup >>> [ 9.088772] bad because of flags: >>> [ 9.089731] flags: 0x21(locked|lru) >>> [ 9.090818] page->mem_cgroup:f2c3e400 >> >> It's also still locked and on the LRU. This page shouldn't have been >> freed. >> >>> [ 9.117848] Call Trace: >>> [ 9.118738] [<c0aa22c9>] dump_stack+0x41/0x52 >>> [ 9.120034] [<c054e30a>] bad_page.part.80+0xaa/0x100 >>> [ 9.121461] [<c054eea9>] free_pages_prepare+0x3b9/0x3f0 >>> [ 9.122934] [<c054fae2>] free_hot_cold_page+0x22/0x160 >>> [ 9.124400] [<c071a22f>] ? copy_to_iter+0x1af/0x2a0 >>> [ 9.125750] [<c054c4a3>] ? mempool_free_slab+0x13/0x20 >>> [ 9.126840] [<c054fc57>] __free_pages+0x37/0x50 >>> [ 9.127849] [<c054c4fd>] mempool_free_pages+0xd/0x10 >>> [ 9.128908] [<c054c8b6>] mempool_free+0x26/0x80 >>> [ 9.129895] [<c06f77e6>] bounce_end_io+0x56/0x80 >> >> The page state looks completely off for a bounce buffer page. Did >> somebody mess with a bounce bio's bv_page? > > Looks the page isn't touched in both lo_read_transfer() and > lo_read_simple(). > > Maybe it is related with aa4d86163e4e(block: loop: switch to VFS ITER_BVEC), > or it might be helpful to run 'git bisect' if reverting aa4d86163e4e can't > fix the issue, suppose the issue can be reproduced easily.
I can try reverting that and getting someone to test it. It is somewhat complicated by having to spin a new install ISO, so a report back will be somewhat delayed. In the meantime, I'm also asking people to track down the first kernel build that hits this, so hopefully that gives us more of a clue as well. It is odd that only 32-bit hits this issue though. At least from what we've seen thus far. josh -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
