* khugepaged might_sleep() warn due to CONFIG_HIGHPTE=y
@ 2019-10-29 20:15 Ville Syrjälä
2019-10-29 21:02 ` Andrew Morton
2019-10-29 23:15 ` khugepaged might_sleep() warn due to CONFIG_HIGHPTE=y Jason Gunthorpe
0 siblings, 2 replies; 6+ messages in thread
From: Ville Syrjälä @ 2019-10-29 20:15 UTC (permalink / raw)
To: linux-kernel
Cc: Andrew Morton, Kirill A. Shutemov, Thomas Gleixner, Ingo Molnar,
Borislav Petkov, H. Peter Anvin, linux-mm
Hi,
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().
My naive idea would be to just reorder those things, but not sure
if there's some magic ordering constraint here. At least the machine
still boots when I do it :)
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 0a1b4b484ac5..f05d27b7183d 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -1028,12 +1028,13 @@ static void collapse_huge_page(struct mm_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
--
Ville Syrjälä
Intel
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: khugepaged might_sleep() warn due to CONFIG_HIGHPTE=y
2019-10-29 20:15 khugepaged might_sleep() warn due to CONFIG_HIGHPTE=y Ville Syrjälä
@ 2019-10-29 21:02 ` Andrew Morton
2019-10-29 21:25 ` [PATCH] mm/khugepaged: Fix might_sleep() warn with CONFIG_HIGHPTE=y Ville Syrjala
2019-10-29 23:15 ` khugepaged might_sleep() warn due to CONFIG_HIGHPTE=y Jason Gunthorpe
1 sibling, 1 reply; 6+ messages in thread
From: Andrew Morton @ 2019-10-29 21:02 UTC (permalink / raw)
To: Ville Syrjälä
Cc: linux-kernel, Kirill A. Shutemov, Thomas Gleixner, Ingo Molnar,
Borislav Petkov, H. Peter Anvin, linux-mm,
Jérôme Glisse, Ralph Campbell, Ira Weiny,
Jason Gunthorpe, Daniel Vetter, Andrea Arcangeli
On Tue, 29 Oct 2019 22:15:13 +0200 Ville Syrjälä <ville.syrjala@linux.intel.com> wrote:
> Hi,
>
> 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().
>
> My naive idea would be to just reorder those things, but not sure
> if there's some magic ordering constraint here. At least the machine
> still boots when I do it :)
>
> diff --git a/mm/khugepaged.c b/mm/khugepaged.c
> index 0a1b4b484ac5..f05d27b7183d 100644
> --- a/mm/khugepaged.c
> +++ b/mm/khugepaged.c
> @@ -1028,12 +1028,13 @@ static void collapse_huge_page(struct mm_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
>
Looks good to me. Can you resend it with a signoff please?
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH] mm/khugepaged: Fix might_sleep() warn with CONFIG_HIGHPTE=y
2019-10-29 21:02 ` Andrew Morton
@ 2019-10-29 21:25 ` Ville Syrjala
2019-10-29 21:43 ` Andrew Morton
2019-10-30 7:08 ` Kirill A. Shutemov
0 siblings, 2 replies; 6+ messages in thread
From: Ville Syrjala @ 2019-10-29 21:25 UTC (permalink / raw)
To: linux-kernel
Cc: Andrew Morton, Kirill A. Shutemov, Thomas Gleixner, Ingo Molnar,
Borislav Petkov, H. Peter Anvin, linux-mm,
Ville Syrjälä
From: Ville Syrjälä <ville.syrjala@linux.intel.com>
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(). Let's do the naive approach
and just reorder the two operations.
Cc: linux-kernel@vger.kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: linux-mm@kvack.org
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
mm/khugepaged.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 0a1b4b484ac5..f05d27b7183d 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -1028,12 +1028,13 @@ static void collapse_huge_page(struct mm_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
--
2.23.0
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] mm/khugepaged: Fix might_sleep() warn with CONFIG_HIGHPTE=y
2019-10-29 21:25 ` [PATCH] mm/khugepaged: Fix might_sleep() warn with CONFIG_HIGHPTE=y Ville Syrjala
@ 2019-10-29 21:43 ` Andrew Morton
2019-10-30 7:08 ` Kirill A. Shutemov
1 sibling, 0 replies; 6+ messages in thread
From: Andrew Morton @ 2019-10-29 21:43 UTC (permalink / raw)
To: Ville Syrjala
Cc: linux-kernel, Kirill A. Shutemov, Thomas Gleixner, Ingo Molnar,
Borislav Petkov, H. Peter Anvin, linux-mm,
Jérôme Glisse, Ralph Campbell, Ira Weiny,
Jason Gunthorpe, Daniel Vetter, Andrea Arcangeli
On Tue, 29 Oct 2019 23:25:13 +0200 Ville Syrjala <ville.syrjala@linux.intel.com> wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
>
> 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(). Let's do the naive approach
> and just reorder the two operations.
Thanks.
I'll add
Fixes: 810e24e009cf71 ("mm/mmu_notifiers: annotate with might_sleep()")
Cc: <stable@vger.kernel.org>
although 810e24e009cf71 merely exposed the bug.
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] mm/khugepaged: Fix might_sleep() warn with CONFIG_HIGHPTE=y
2019-10-29 21:25 ` [PATCH] mm/khugepaged: Fix might_sleep() warn with CONFIG_HIGHPTE=y Ville Syrjala
2019-10-29 21:43 ` Andrew Morton
@ 2019-10-30 7:08 ` Kirill A. Shutemov
1 sibling, 0 replies; 6+ messages in thread
From: Kirill A. Shutemov @ 2019-10-30 7:08 UTC (permalink / raw)
To: Ville Syrjala
Cc: linux-kernel, Andrew Morton, Kirill A. Shutemov, Thomas Gleixner,
Ingo Molnar, Borislav Petkov, H. Peter Anvin, linux-mm
On Tue, Oct 29, 2019 at 11:25:13PM +0200, Ville Syrjala wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
>
> 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(). Let's do the naive approach
> and just reorder the two operations.
>
> Cc: linux-kernel@vger.kernel.org
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: Borislav Petkov <bp@alien8.de>
> Cc: "H. Peter Anvin" <hpa@zytor.com>
> Cc: linux-mm@kvack.org
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
--
Kirill A. Shutemov
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: khugepaged might_sleep() warn due to CONFIG_HIGHPTE=y
2019-10-29 20:15 khugepaged might_sleep() warn due to CONFIG_HIGHPTE=y Ville Syrjälä
2019-10-29 21:02 ` Andrew Morton
@ 2019-10-29 23:15 ` Jason Gunthorpe
1 sibling, 0 replies; 6+ messages in thread
From: Jason Gunthorpe @ 2019-10-29 23:15 UTC (permalink / raw)
To: Ville Syrjälä
Cc: linux-kernel, Andrew Morton, Kirill A. Shutemov, Thomas Gleixner,
Ingo Molnar, Borislav Petkov, H. Peter Anvin, linux-mm
On Tue, Oct 29, 2019 at 10:15:13PM +0200, Ville Syrjälä wrote:
> Hi,
>
> 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().
>
> My naive idea would be to just reorder those things, but not sure
> if there's some magic ordering constraint here. At least the machine
> still boots when I do it :)
>
> diff --git a/mm/khugepaged.c b/mm/khugepaged.c
> index 0a1b4b484ac5..f05d27b7183d 100644
> +++ b/mm/khugepaged.c
> @@ -1028,12 +1028,13 @@ static void collapse_huge_page(struct mm_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);
> +
Since pte and pte_ptl don't leak into invalidate_range_start this
seems reasonable to me..
Good catch with the new debugging!
Jason
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2019-10-30 7:08 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-10-29 20:15 khugepaged might_sleep() warn due to CONFIG_HIGHPTE=y Ville Syrjälä
2019-10-29 21:02 ` Andrew Morton
2019-10-29 21:25 ` [PATCH] mm/khugepaged: Fix might_sleep() warn with CONFIG_HIGHPTE=y Ville Syrjala
2019-10-29 21:43 ` Andrew Morton
2019-10-30 7:08 ` Kirill A. Shutemov
2019-10-29 23:15 ` khugepaged might_sleep() warn due to CONFIG_HIGHPTE=y Jason Gunthorpe
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