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]
Regards
Zdenek
