* [PATCH] mm: document mmu_notifier_invalidate_range_start_nonblock()
@ 2023-09-18 20:18 Jann Horn
2023-09-18 23:26 ` Jason Gunthorpe
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: Jann Horn @ 2023-09-18 20:18 UTC (permalink / raw)
To: Andrew Morton; +Cc: Alistair Popple, Jason Gunthorpe, linux-kernel, linux-mm
Document what mmu_notifier_invalidate_range_start_nonblock() is for.
Also add a __must_check annotation to signal that callers must bail out if
a notifier vetoes the operation.
Signed-off-by: Jann Horn <jannh@google.com>
---
include/linux/mmu_notifier.h | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h
index 6e3c857606f1..f349e08a9dfe 100644
--- a/include/linux/mmu_notifier.h
+++ b/include/linux/mmu_notifier.h
@@ -459,7 +459,14 @@ mmu_notifier_invalidate_range_start(struct mmu_notifier_range *range)
lock_map_release(&__mmu_notifier_invalidate_range_start_map);
}
-static inline int
+/*
+ * This version of mmu_notifier_invalidate_range_start() avoids blocking, but it
+ * can return an error if a notifier can't proceed without blocking, in which
+ * case you're not allowed to modify PTEs in the specified range.
+ *
+ * This is mainly intended for OOM handling.
+ */
+static inline int __must_check
mmu_notifier_invalidate_range_start_nonblock(struct mmu_notifier_range *range)
{
int ret = 0;
base-commit: 6704c78e2963a5682b4ac3c0e609d36f2405cf17
--
2.42.0.459.ge4e396fd5e-goog
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] mm: document mmu_notifier_invalidate_range_start_nonblock()
2023-09-18 20:18 [PATCH] mm: document mmu_notifier_invalidate_range_start_nonblock() Jann Horn
@ 2023-09-18 23:26 ` Jason Gunthorpe
2023-09-19 0:08 ` Alistair Popple
2023-11-14 15:32 ` David Hildenbrand
2 siblings, 0 replies; 4+ messages in thread
From: Jason Gunthorpe @ 2023-09-18 23:26 UTC (permalink / raw)
To: Jann Horn; +Cc: Andrew Morton, Alistair Popple, linux-kernel, linux-mm
On Mon, Sep 18, 2023 at 10:18:32PM +0200, Jann Horn wrote:
> Document what mmu_notifier_invalidate_range_start_nonblock() is for.
> Also add a __must_check annotation to signal that callers must bail out if
> a notifier vetoes the operation.
>
> Signed-off-by: Jann Horn <jannh@google.com>
> ---
> include/linux/mmu_notifier.h | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Jason
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] mm: document mmu_notifier_invalidate_range_start_nonblock()
2023-09-18 20:18 [PATCH] mm: document mmu_notifier_invalidate_range_start_nonblock() Jann Horn
2023-09-18 23:26 ` Jason Gunthorpe
@ 2023-09-19 0:08 ` Alistair Popple
2023-11-14 15:32 ` David Hildenbrand
2 siblings, 0 replies; 4+ messages in thread
From: Alistair Popple @ 2023-09-19 0:08 UTC (permalink / raw)
To: Jann Horn; +Cc: Andrew Morton, Jason Gunthorpe, linux-kernel, linux-mm
Looks good, thanks.
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Jann Horn <jannh@google.com> writes:
> Document what mmu_notifier_invalidate_range_start_nonblock() is for.
> Also add a __must_check annotation to signal that callers must bail out if
> a notifier vetoes the operation.
>
> Signed-off-by: Jann Horn <jannh@google.com>
> ---
> include/linux/mmu_notifier.h | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h
> index 6e3c857606f1..f349e08a9dfe 100644
> --- a/include/linux/mmu_notifier.h
> +++ b/include/linux/mmu_notifier.h
> @@ -459,7 +459,14 @@ mmu_notifier_invalidate_range_start(struct mmu_notifier_range *range)
> lock_map_release(&__mmu_notifier_invalidate_range_start_map);
> }
>
> -static inline int
> +/*
> + * This version of mmu_notifier_invalidate_range_start() avoids blocking, but it
> + * can return an error if a notifier can't proceed without blocking, in which
> + * case you're not allowed to modify PTEs in the specified range.
> + *
> + * This is mainly intended for OOM handling.
> + */
> +static inline int __must_check
> mmu_notifier_invalidate_range_start_nonblock(struct mmu_notifier_range *range)
> {
> int ret = 0;
>
> base-commit: 6704c78e2963a5682b4ac3c0e609d36f2405cf17
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] mm: document mmu_notifier_invalidate_range_start_nonblock()
2023-09-18 20:18 [PATCH] mm: document mmu_notifier_invalidate_range_start_nonblock() Jann Horn
2023-09-18 23:26 ` Jason Gunthorpe
2023-09-19 0:08 ` Alistair Popple
@ 2023-11-14 15:32 ` David Hildenbrand
2 siblings, 0 replies; 4+ messages in thread
From: David Hildenbrand @ 2023-11-14 15:32 UTC (permalink / raw)
To: Jann Horn, Andrew Morton
Cc: Alistair Popple, Jason Gunthorpe, linux-kernel, linux-mm
On 18.09.23 22:18, Jann Horn wrote:
> Document what mmu_notifier_invalidate_range_start_nonblock() is for.
> Also add a __must_check annotation to signal that callers must bail out if
> a notifier vetoes the operation.
>
> Signed-off-by: Jann Horn <jannh@google.com>
> ---
I'm late but:
Reviewed-by: David Hildenbrand <david@redhat.com>
--
Cheers,
David / dhildenb
^ permalink raw reply [flat|nested] 4+ messages in thread
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2023-09-18 20:18 [PATCH] mm: document mmu_notifier_invalidate_range_start_nonblock() Jann Horn
2023-09-18 23:26 ` Jason Gunthorpe
2023-09-19 0:08 ` Alistair Popple
2023-11-14 15:32 ` David Hildenbrand
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