The patch titled
Subject: khugepaged might_sleep() warn due to CONFIG_HIGHPTE=y
has been added to the -mm tree. Its filename is
khugepaged-might_sleep-warn-due-to-config_highpte=y.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/khugepaged-might_sleep-warn-due-to-config_highpte%3Dy.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/khugepaged-might_sleep-warn-due-to-config_highpte%3Dy.patch
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------------------------------------------------------
From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Subject: khugepaged might_sleep() warn due to CONFIG_HIGHPTE=y
I got some khugepaged spew on a 32bit x86:
[ 217.490026] BUG: sleeping function called from invalid context at include/linux/mmu_notifier.h:346
[ 217.492826] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 25, name: khugepaged
[ 217.495589] INFO: lockdep is turned off.
[ 217.498371] CPU: 1 PID: 25 Comm: khugepaged Not tainted 5.4.0-rc5-elk+ #206
[ 217.501233] Hardware name: System manufacturer P5Q-EM/P5Q-EM, BIOS 2203 07/08/2009
[ 217.501697] Call Trace:
[ 217.501697] dump_stack+0x66/0x8e
[ 217.501697] ___might_sleep.cold.96+0x95/0xa6
[ 217.501697] __might_sleep+0x2e/0x80
[ 217.501697] collapse_huge_page.isra.51+0x5ac/0x1360
[ 217.501697] ? __alloc_pages_nodemask+0xec/0xf80
[ 217.501697] ? __alloc_pages_nodemask+0x191/0xf80
[ 217.501697] ? trace_hardirqs_on+0x4a/0xf0
[ 217.501697] khugepaged+0x9a9/0x20f0
[ 217.501697] ? _raw_spin_unlock+0x21/0x30
[ 217.501697] ? trace_hardirqs_on+0x4a/0xf0
[ 217.501697] ? wait_woken+0xa0/0xa0
[ 217.501697] kthread+0xf5/0x110
[ 217.501697] ? collapse_pte_mapped_thp+0x3b0/0x3b0
[ 217.501697] ? kthread_create_worker_on_cpu+0x20/0x20
[ 217.501697] ret_from_fork+0x2e/0x38
Looks like it's due to CONFIG_HIGHPTE=y pte_offset_map()->kmap_atomic() vs.
mmu_notifier_invalidate_range_start().
Link: http://lkml.kernel.org/r/20191029201513.GG1208@xxxxxxxxx
Cc: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Jérôme Glisse <jglisse@xxxxxxxxxx>
Cc: Ralph Campbell <rcampbell@xxxxxxxxxx>
Cc: Ira Weiny <ira.weiny@xxxxxxxxx>
Cc: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
Cc: Daniel Vetter <daniel.vetter@xxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/khugepaged.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
--- a/mm/khugepaged.c~khugepaged-might_sleep-warn-due-to-config_highpte=y
+++ a/mm/khugepaged.c
@@ -1028,12 +1028,13 @@ static void collapse_huge_page(struct mm
anon_vma_lock_write(vma->anon_vma);
- pte = pte_offset_map(pmd, address);
- pte_ptl = pte_lockptr(mm, pmd);
-
mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, NULL, mm,
address, address + HPAGE_PMD_SIZE);
mmu_notifier_invalidate_range_start(&range);
+
+ pte = pte_offset_map(pmd, address);
+ pte_ptl = pte_lockptr(mm, pmd);
+
pmd_ptl = pmd_lock(mm, pmd); /* probably unnecessary */
/*
* After this gup_fast can't run anymore. This also removes
_
Patches currently in -mm which might be from ville.syrjala@xxxxxxxxxxxxxxx are
khugepaged-might_sleep-warn-due-to-config_highpte=y.patch
