| Message ID | 20240516122608.22610-1-linmiaohe@huawei.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v3] mm/huge_memory: don't unpoison huge_zero_folio | expand |
On 5/16/24 17:56, Miaohe Lin wrote: > When I did memory failure tests recently, below panic occurs: > > kernel BUG at include/linux/mm.h:1135! > invalid opcode: 0000 [#1] PREEMPT SMP NOPTI > CPU: 9 PID: 137 Comm: kswapd1 Not tainted 6.9.0-rc4-00491-gd5ce28f156fe-dirty #14 > RIP: 0010:shrink_huge_zero_page_scan+0x168/0x1a0 > RSP: 0018:ffff9933c6c57bd0 EFLAGS: 00000246 > RAX: 000000000000003e RBX: 0000000000000000 RCX: ffff88f61fc5c9c8 > RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff88f61fc5c9c0 > RBP: ffffcd7c446b0000 R08: ffffffff9a9405f0 R09: 0000000000005492 > R10: 00000000000030ea R11: ffffffff9a9405f0 R12: 0000000000000000 > R13: 0000000000000000 R14: 0000000000000000 R15: ffff88e703c4ac00 > FS: 0000000000000000(0000) GS:ffff88f61fc40000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 000055f4da6e9878 CR3: 0000000c71048000 CR4: 00000000000006f0 > Call Trace: > <TASK> > do_shrink_slab+0x14f/0x6a0 > shrink_slab+0xca/0x8c0 > shrink_node+0x2d0/0x7d0 > balance_pgdat+0x33a/0x720 > kswapd+0x1f3/0x410 > kthread+0xd5/0x100 > ret_from_fork+0x2f/0x50 > ret_from_fork_asm+0x1a/0x30 > </TASK> > Modules linked in: mce_inject hwpoison_inject > ---[ end trace 0000000000000000 ]--- > RIP: 0010:shrink_huge_zero_page_scan+0x168/0x1a0 > RSP: 0018:ffff9933c6c57bd0 EFLAGS: 00000246 > RAX: 000000000000003e RBX: 0000000000000000 RCX: ffff88f61fc5c9c8 > RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff88f61fc5c9c0 > RBP: ffffcd7c446b0000 R08: ffffffff9a9405f0 R09: 0000000000005492 > R10: 00000000000030ea R11: ffffffff9a9405f0 R12: 0000000000000000 > R13: 0000000000000000 R14: 0000000000000000 R15: ffff88e703c4ac00 > FS: 0000000000000000(0000) GS:ffff88f61fc40000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 000055f4da6e9878 CR3: 0000000c71048000 CR4: 00000000000006f0 > > The root cause is that HWPoison flag will be set for huge_zero_folio > without increasing the folio refcnt. But then unpoison_memory() will > decrease the folio refcnt unexpectly as it appears like a successfully Small nit, a typo in here ^^^^^ s/unexpectly/unexpectedly/. > hwpoisoned folio leading to VM_BUG_ON_PAGE(page_ref_count(page) == 0) > when releasing huge_zero_folio. > > Skip unpoisoning huge_zero_folio in unpoison_memory() to fix this issue. > We're not prepared to unpoison huge_zero_folio yet. > > Fixes: 478d134e9506 ("mm/huge_memory: do not overkill when splitting huge_zero_page") The target commit looks right. > Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> > Acked-by: David Hildenbrand <david@redhat.com> > Reviewed-by: Yang Shi <shy828301@gmail.com> > Reviewed-by: Oscar Salvador <osalvador@suse.de> > Cc: <stable@vger.kernel.org> > --- > v3: > Move up is_huge_zero_folio() check and change return value to > -EOPNOTSUPP per Oscar. > Collect Reviewed-by and Acked-by tag. Thanks. > v2: > Change to simply check for the huge zero page per David. Thanks. > --- > mm/memory-failure.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/mm/memory-failure.c b/mm/memory-failure.c > index 16ada4fb02b7..a9fe9eda593f 100644 > --- a/mm/memory-failure.c > +++ b/mm/memory-failure.c > @@ -2546,6 +2546,13 @@ int unpoison_memory(unsigned long pfn) > goto unlock_mutex; > } > > + if (is_huge_zero_folio(folio)) { > + unpoison_pr_info("Unpoison: huge zero page is not supported %#lx\n", > + pfn, &unpoison_rs); > + ret = -EOPNOTSUPP; > + goto unlock_mutex; > + } > + > if (!PageHWPoison(p)) { > unpoison_pr_info("Unpoison: Page was already unpoisoned %#lx\n", > pfn, &unpoison_rs); This patch applies on latest linux-next but not on latest mainline as is_huge_zero_folio() is absent there. Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
On 2024/5/17 15:02, Anshuman Khandual wrote: > On 5/16/24 17:56, Miaohe Lin wrote: >> When I did memory failure tests recently, below panic occurs: >> >> kernel BUG at include/linux/mm.h:1135! >> invalid opcode: 0000 [#1] PREEMPT SMP NOPTI >> CPU: 9 PID: 137 Comm: kswapd1 Not tainted 6.9.0-rc4-00491-gd5ce28f156fe-dirty #14 >> RIP: 0010:shrink_huge_zero_page_scan+0x168/0x1a0 >> RSP: 0018:ffff9933c6c57bd0 EFLAGS: 00000246 >> RAX: 000000000000003e RBX: 0000000000000000 RCX: ffff88f61fc5c9c8 >> RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff88f61fc5c9c0 >> RBP: ffffcd7c446b0000 R08: ffffffff9a9405f0 R09: 0000000000005492 >> R10: 00000000000030ea R11: ffffffff9a9405f0 R12: 0000000000000000 >> R13: 0000000000000000 R14: 0000000000000000 R15: ffff88e703c4ac00 >> FS: 0000000000000000(0000) GS:ffff88f61fc40000(0000) knlGS:0000000000000000 >> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >> CR2: 000055f4da6e9878 CR3: 0000000c71048000 CR4: 00000000000006f0 >> Call Trace: >> <TASK> >> do_shrink_slab+0x14f/0x6a0 >> shrink_slab+0xca/0x8c0 >> shrink_node+0x2d0/0x7d0 >> balance_pgdat+0x33a/0x720 >> kswapd+0x1f3/0x410 >> kthread+0xd5/0x100 >> ret_from_fork+0x2f/0x50 >> ret_from_fork_asm+0x1a/0x30 >> </TASK> >> Modules linked in: mce_inject hwpoison_inject >> ---[ end trace 0000000000000000 ]--- >> RIP: 0010:shrink_huge_zero_page_scan+0x168/0x1a0 >> RSP: 0018:ffff9933c6c57bd0 EFLAGS: 00000246 >> RAX: 000000000000003e RBX: 0000000000000000 RCX: ffff88f61fc5c9c8 >> RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff88f61fc5c9c0 >> RBP: ffffcd7c446b0000 R08: ffffffff9a9405f0 R09: 0000000000005492 >> R10: 00000000000030ea R11: ffffffff9a9405f0 R12: 0000000000000000 >> R13: 0000000000000000 R14: 0000000000000000 R15: ffff88e703c4ac00 >> FS: 0000000000000000(0000) GS:ffff88f61fc40000(0000) knlGS:0000000000000000 >> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >> CR2: 000055f4da6e9878 CR3: 0000000c71048000 CR4: 00000000000006f0 >> >> The root cause is that HWPoison flag will be set for huge_zero_folio >> without increasing the folio refcnt. But then unpoison_memory() will >> decrease the folio refcnt unexpectly as it appears like a successfully > > Small nit, a typo in here ^^^^^ s/unexpectly/unexpectedly/. Thanks for finding out this typo. And thanks Andrew for fixing the typo. > >> hwpoisoned folio leading to VM_BUG_ON_PAGE(page_ref_count(page) == 0) >> when releasing huge_zero_folio. >> >> Skip unpoisoning huge_zero_folio in unpoison_memory() to fix this issue. >> We're not prepared to unpoison huge_zero_folio yet. >> >> Fixes: 478d134e9506 ("mm/huge_memory: do not overkill when splitting huge_zero_page") > > The target commit looks right. > >> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> >> Acked-by: David Hildenbrand <david@redhat.com> >> Reviewed-by: Yang Shi <shy828301@gmail.com> >> Reviewed-by: Oscar Salvador <osalvador@suse.de> >> Cc: <stable@vger.kernel.org> >> --- >> v3: >> Move up is_huge_zero_folio() check and change return value to >> -EOPNOTSUPP per Oscar. >> Collect Reviewed-by and Acked-by tag. Thanks. >> v2: >> Change to simply check for the huge zero page per David. Thanks. >> --- >> mm/memory-failure.c | 7 +++++++ >> 1 file changed, 7 insertions(+) >> >> diff --git a/mm/memory-failure.c b/mm/memory-failure.c >> index 16ada4fb02b7..a9fe9eda593f 100644 >> --- a/mm/memory-failure.c >> +++ b/mm/memory-failure.c >> @@ -2546,6 +2546,13 @@ int unpoison_memory(unsigned long pfn) >> goto unlock_mutex; >> } >> >> + if (is_huge_zero_folio(folio)) { >> + unpoison_pr_info("Unpoison: huge zero page is not supported %#lx\n", >> + pfn, &unpoison_rs); >> + ret = -EOPNOTSUPP; >> + goto unlock_mutex; >> + } >> + >> if (!PageHWPoison(p)) { >> unpoison_pr_info("Unpoison: Page was already unpoisoned %#lx\n", >> pfn, &unpoison_rs); > > This patch applies on latest linux-next but not on latest mainline as > is_huge_zero_folio() is absent there. It could be simply replaced with is_huge_zero_page(). > > Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Thanks. .
diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 16ada4fb02b7..a9fe9eda593f 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -2546,6 +2546,13 @@ int unpoison_memory(unsigned long pfn) goto unlock_mutex; } + if (is_huge_zero_folio(folio)) { + unpoison_pr_info("Unpoison: huge zero page is not supported %#lx\n", + pfn, &unpoison_rs); + ret = -EOPNOTSUPP; + goto unlock_mutex; + } + if (!PageHWPoison(p)) { unpoison_pr_info("Unpoison: Page was already unpoisoned %#lx\n", pfn, &unpoison_rs);
When I did memory failure tests recently, below panic occurs: kernel BUG at include/linux/mm.h:1135! invalid opcode: 0000 [#1] PREEMPT SMP NOPTI CPU: 9 PID: 137 Comm: kswapd1 Not tainted 6.9.0-rc4-00491-gd5ce28f156fe-dirty #14 RIP: 0010:shrink_huge_zero_page_scan+0x168/0x1a0 RSP: 0018:ffff9933c6c57bd0 EFLAGS: 00000246 RAX: 000000000000003e RBX: 0000000000000000 RCX: ffff88f61fc5c9c8 RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff88f61fc5c9c0 RBP: ffffcd7c446b0000 R08: ffffffff9a9405f0 R09: 0000000000005492 R10: 00000000000030ea R11: ffffffff9a9405f0 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: ffff88e703c4ac00 FS: 0000000000000000(0000) GS:ffff88f61fc40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055f4da6e9878 CR3: 0000000c71048000 CR4: 00000000000006f0 Call Trace: <TASK> do_shrink_slab+0x14f/0x6a0 shrink_slab+0xca/0x8c0 shrink_node+0x2d0/0x7d0 balance_pgdat+0x33a/0x720 kswapd+0x1f3/0x410 kthread+0xd5/0x100 ret_from_fork+0x2f/0x50 ret_from_fork_asm+0x1a/0x30 </TASK> Modules linked in: mce_inject hwpoison_inject ---[ end trace 0000000000000000 ]--- RIP: 0010:shrink_huge_zero_page_scan+0x168/0x1a0 RSP: 0018:ffff9933c6c57bd0 EFLAGS: 00000246 RAX: 000000000000003e RBX: 0000000000000000 RCX: ffff88f61fc5c9c8 RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff88f61fc5c9c0 RBP: ffffcd7c446b0000 R08: ffffffff9a9405f0 R09: 0000000000005492 R10: 00000000000030ea R11: ffffffff9a9405f0 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: ffff88e703c4ac00 FS: 0000000000000000(0000) GS:ffff88f61fc40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055f4da6e9878 CR3: 0000000c71048000 CR4: 00000000000006f0 The root cause is that HWPoison flag will be set for huge_zero_folio without increasing the folio refcnt. But then unpoison_memory() will decrease the folio refcnt unexpectly as it appears like a successfully hwpoisoned folio leading to VM_BUG_ON_PAGE(page_ref_count(page) == 0) when releasing huge_zero_folio. Skip unpoisoning huge_zero_folio in unpoison_memory() to fix this issue. We're not prepared to unpoison huge_zero_folio yet. Fixes: 478d134e9506 ("mm/huge_memory: do not overkill when splitting huge_zero_page") Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Yang Shi <shy828301@gmail.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: <stable@vger.kernel.org> --- v3: Move up is_huge_zero_folio() check and change return value to -EOPNOTSUPP per Oscar. Collect Reviewed-by and Acked-by tag. Thanks. v2: Change to simply check for the huge zero page per David. Thanks. --- mm/memory-failure.c | 7 +++++++ 1 file changed, 7 insertions(+)