9:34 p.m.
kernel test robot <xiaolong.ye(a)intel.com> writes:
FYI, we noticed the following commit:
https://github.com/0day-ci/linux
Aneesh-Kumar-K-V/mm-Use-the-correct-page-size-when-removing-the-page/20161012-013446
commit c4344e80359420d7574b3b90fddf53311f1d24e6 ("mm: Remove the page size change
check in tlb_remove_page")
in testcase: boot
on test machine: qemu-system-i386 -enable-kvm -cpu Haswell,+smep,+smap -m 360M
caused below changes:
+------------------------------------------------+------------+------------+
| | eff764128d | c4344e8035 |
+------------------------------------------------+------------+------------+
| boot_successes | 59 | 0 |
| boot_failures | 0 | 43 |
| WARNING:at_mm/memory.c:#__tlb_remove_page_size | 0 | 43 |
| calltrace:SyS_execve | 0 | 43 |
| calltrace:run_init_process | 0 | 21 |
+------------------------------------------------+------------+------------+
[ 4.096204] Write protecting the kernel text: 3148k
[ 4.096911] Write protecting the kernel read-only data: 1444k
[ 4.120357] ------------[ cut here ]------------
[ 4.121078] WARNING: CPU: 0 PID: 101 at mm/memory.c:303
__tlb_remove_page_size+0x25/0x99
[ 4.122380] Modules linked in:
[ 4.122788] CPU: 0 PID: 101 Comm: run-parts Not tainted 4.8.0-mm1-00315-gc4344e8 #5
[ 4.123956] bd145dc4 b111e5e6 bd145de0 b10320dc 0000012f b10974d1 bd145e70 c4954170
[ 4.125277] c4954170 bd145df4 b103215f 00000009 00000000 00000000 bd145e04 b10974d1
[ 4.126424] c4954170 bd145e70 bd145e14 b10263ca bd145e70 bd47bafc bd145e40 b109767a
[ 4.127622] Call Trace:
Thanks for the report. The below change should fix this.
commit 18c929e7cf672da617dc218c6265366bf78b1644
Author: Aneesh Kumar K.V <aneesh.kumar(a)linux.vnet.ibm.com>
Date: Wed Oct 12 08:40:41 2016 +0530
update mmu gather page size before flushing page table cache
diff --git a/mm/memory.c b/mm/memory.c
index 26d1ba8c87e6..7e7eccb82a2b 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -526,7 +526,11 @@ void free_pgd_range(struct mmu_gather *tlb,
end -= PMD_SIZE;
if (addr > end - 1)
return;
-
+ /*
+ * We add page table cache pages with PAGE_SIZE,
+ * (see pte_free_tlb()), flush the tlb if we need
+ */
+ tlb_remove_check_page_size_change(tlb, PAGE_SIZE);
pgd = pgd_offset(tlb->mm, addr);
do {
next = pgd_addr_end(addr, end);