On Wed, 10 Aug 2022, Zdenek Kabelac wrote: > Dne 22. 06. 22 v 13:18 Zdenek Kabelac napsal(a): > > Hello > > > > While somewhat oldish hw (T61, 4G, C2D) - I've now witnessed new crash with > > Xorg: > > > > (happened while reopening iconified Firefox window - running 'standard' > > rawhide -nodebug kernel 5.19.0-0.rc2.21.fc37.x86_64) > > > > Hello > > > Ok, I think I now know what is behind this BUG/crash of intel graphics - > interestingly it took me a few weeks to realize this. > > So I've actually installed with some Rawhide update 'zram-generator' package > to use zram swap to help with memory of Firefox & Thunderbird a bit with this > 4G RAM laptop. All worked fine. However side effect of usage of ZRAM swapping > became actually this occasional kernel BUG hitting. > > When I've stopped using Zram swap - it now runs for 2 weeks without a > single deadlock - with single or dual screen monitor setup with many suspends > & resumes in between. > > So I'm likely 100% sure that ZRAM usage is triggering this issue. While I > know this laptop is old and likely with low memory and so on - no sure if it's > worth to solve it - maybe good enough solution is to issue a warning user > should no comibine this old piece with ZRAM - but I'm all open to do some > testing for fix - although I still don't have a simple triggering path for > this issue to happen within short period of time. > > Maybe driver is missing tomark some pages as pined into memory so ZRAM can't > swap them out ?. > > > > page:00000000577758b3 refcount:0 mapcount:0 mapping:0000000000000000 > > index:0x1 pfn:0x1192cc > > flags: 0x17ffffc0000000(node=0|zone=2|lastcpupid=0x1fffff) > > raw: 0017ffffc0000000 ffffe683c47171c8 ffff8fa3f79377a8 0000000000000000 > > raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000 > > page dumped because: VM_BUG_ON_FOLIO(!folio_test_locked(folio)) > > ------------[ cut here ]------------ > > kernel BUG at mm/shmem.c:708! > > invalid opcode: 0000 [#1] PREEMPT SMP NOPTI > > CPU: 1 PID: 42896 Comm: Xorg Not tainted 5.19.0-0.rc2.21.fc37.x86_64 #1 > > Hardware name: LENOVO 6464CTO/6464CTO, BIOS 7LETC9WW (2.29 ) 03/18/2011 > > RIP: 0010:shmem_add_to_page_cache+0x48e/0x500 > > Code: 01 0f 84 0a fc ff ff 48 8d 4a ff 31 d2 48 39 cb 0f 85 ff fb ff ff e9 > > f6 fb ff ff 48 c7 c6 70 01 64 bb 48 89 df e8 f2 99 01 00 <0f> 0b 48 c7 c6 a0 > > 1b 64 bb 48 89 df e8 e1 99 01 00 0f 0b 48 8b 13 > > RSP: 0018:ffff9ce7c047f6b0 EFLAGS: 00010286 > > RAX: 000000000000003f RBX: ffffe683c464b300 RCX: 0000000000000000 > > RDX: 0000000000000001 RSI: ffffffffbb67b8e8 RDI: 00000000ffffffff > > RBP: 0000000000023f97 R08: ffffffffbca122a0 R09: 64656b636f6c5f74 > > R10: 747365745f6f696c R11: 6f6621284f494c4f R12: 00000000001120d4 > > R13: ffff8fa2c6ae7890 R14: ffffe683c464b300 R15: 0000000000000001 > > FS: 00007fc1cea31380(0000) GS:ffff8fa3f7900000(0000) > > knlGS:0000000000000000 > > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > CR2: 00007f6972e228c8 CR3: 0000000104ba8000 CR4: 00000000000006e0 > > Call Trace: > > <TASK> > > shmem_swapin_folio+0x274/0x980 > > shmem_getpage_gfp+0x234/0x990 > > shmem_read_mapping_page_gfp+0x36/0xf0 > > shmem_sg_alloc_table+0x11b/0x250 [i915] Sorry, I never noticed your original report in June. This is not a bug in zram or i915, but what Matthew fixes in https://lore.kernel.org/lkml/20220730042518.1264767-1-willy@xxxxxxxxxxxxx/ I am a little surprised to see it hitting i915, since I had thought it could only affect gma500: but looks like 965gm has similar limitations, and so I expect that's what's on your laptop there. Hugh
