On (04/15/15 16:16), Minchan Kim wrote: > On Tue, Apr 14, 2015 at 11:36:57AM -0700, Luigi Semenzato wrote: > > We are seeing several instances of these things (often with different > > but plausible values in the struct page) in kernel 3.8.11, followed by > > a panic() in release_pages a few seconds later. > > > > I realize it's an old kernel and probably of little interest here, but > > I would be most grateful for any pointers on how to proceed. In > > particular, I suspect that many such bugs may have been fixed by now, > > but I am not sure how to find the right fix (which I would backport). > > > > Also, this happens under heavy swap, and we're using zram. I wonder > > if there may be a race condition related to zram which may have been > > fixed since then, and which may result in these symptoms. > > I didn't see such bug until now. Sorry. However, I might miss something > because zram has changed a lot since then. > What I recommend is just to use recent zram/zsmalloc. > I think it's not hard to backport it because they are almost isolated > from other parts in kernel. > If you don't see any problem any more with recent zram, yay, your > system doesn't have any problem. But if you see the problem still, > it means you should suspect another stuffs as culprits as well as > zram. > > Thanks. > assuming that you use zram0, does 'mkswap -c /dev/zram0' show any bad pages right after the swap creation/activation? -ss > > <1>[ 5392.106074] BUG: Bad page state in process CompositorTileW pfn:57a7e > > <1>[ 5392.106109] page:ffffea00015e9f80 count:0 mapcount:0 mapping: > > (null) index:0x2 > > <1>[ 5392.106122] page flags: 0x4000000000000004(referenced) > > <5>[ 5392.106139] Modules linked in: i2c_dev uinput > > snd_hda_codec_realtek memconsole snd_hda_codec_hdmi uvcvideo > > videobuf2_vmalloc videobuf2_memops videobuf2_core videodev > > snd_hda_intel snd_hda_codec snd_hwdep snd_pcm snd_page_alloc snd_timer > > zram(C) lzo_compress zsmalloc(C) fuse nf_conntrack_ipv6 nf_defrag_ipv6 > > ip6table_filter ip6_tables ath9k_btcoex ath9k_common_btcoex > > ath9k_hw_btcoex ath mac80211 cfg80211 option usb_wwan cdc_ether usbnet > > ath3k btusb bluetooth joydev ppp_async ppp_generic slhc tun > > <5>[ 5392.106333] Pid: 27363, comm: CompositorTileW Tainted: G B > > C 3.8.11 #1 > > <5>[ 5392.106344] Call Trace: > > <5>[ 5392.106357] [<ffffffff978ba5bb>] bad_page+0xcf/0xe3 > > <5>[ 5392.106370] [<ffffffff978bb181>] get_page_from_freelist+0x21a/0x46c > > <5>[ 5392.106383] [<ffffffff978beb74>] ? release_pages+0x19b/0x1be > > <5>[ 5392.106394] [<ffffffff978bb5da>] __alloc_pages_nodemask+0x207/0x685 > > <5>[ 5392.106407] [<ffffffff97cb8caf>] ? _cond_resched+0xe/0x1e > > <5>[ 5392.106421] [<ffffffff978d215a>] handle_pte_fault+0x305/0x500 > > <5>[ 5392.106433] [<ffffffff978d4f5e>] ? __vma_link_file+0x65/0x67 > > <5>[ 5392.106445] [<ffffffff978d30d0>] handle_mm_fault+0x97/0xbb > > <5>[ 5392.106459] [<ffffffff97828616>] __do_page_fault+0x1d4/0x38c > > <5>[ 5392.106470] [<ffffffff978d7803>] ? do_mmap_pgoff+0x284/0x2c0 > > <5>[ 5392.106482] [<ffffffff978ca82c>] ? vm_mmap_pgoff+0x7d/0x8e > > <5>[ 5392.106495] [<ffffffff97828800>] do_page_fault+0xe/0x10 > > <5>[ 5392.106506] [<ffffffff97cb9d32>] page_fault+0x22/0x30 -- 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>