* [PATCH] mm: fix misuse of update_mmu_cache() in do_anonymous_page()
@ 2022-09-24 5:32 Qi Zheng
2022-09-25 1:43 ` Muchun Song
0 siblings, 1 reply; 6+ messages in thread
From: Qi Zheng @ 2022-09-24 5:32 UTC (permalink / raw)
To: akpm; +Cc: linux-mm, linux-kernel, muchun.song, Qi Zheng
As message in commit 7df676974359 ("mm/memory.c: Update local TLB
if PTE entry exists") said, we should update local TLB only on the
second thread. So fix the misuse of update_mmu_cache() by using
update_mmu_tlb() in the do_anonymous_page().
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
---
mm/memory.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/memory.c b/mm/memory.c
index 118e5f023597..9e11c783ba0e 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -4122,7 +4122,7 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf)
vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd, vmf->address,
&vmf->ptl);
if (!pte_none(*vmf->pte)) {
- update_mmu_cache(vma, vmf->address, vmf->pte);
+ update_mmu_tlb(vma, vmf->address, vmf->pte);
goto release;
}
--
2.20.1
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH] mm: fix misuse of update_mmu_cache() in do_anonymous_page()
2022-09-24 5:32 [PATCH] mm: fix misuse of update_mmu_cache() in do_anonymous_page() Qi Zheng
@ 2022-09-25 1:43 ` Muchun Song
2022-09-26 8:32 ` David Hildenbrand
0 siblings, 1 reply; 6+ messages in thread
From: Muchun Song @ 2022-09-25 1:43 UTC (permalink / raw)
To: Qi Zheng; +Cc: Andrew Morton, Linux MM, linux-kernel, chris, jcmvbkbc, maobibo
> On Sep 24, 2022, at 13:32, Qi Zheng <zhengqi.arch@bytedance.com> wrote:
>
> As message in commit 7df676974359 ("mm/memory.c: Update local TLB
> if PTE entry exists") said, we should update local TLB only on the
> second thread. So fix the misuse of update_mmu_cache() by using
> update_mmu_tlb() in the do_anonymous_page().
>
> Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
The change looks good to me. However, I am not sure what is the user-visible
effect to xtensa users. So Cc xtensa’s maintainer and the author of 7df676974359
to double check this.
But anyway:
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] mm: fix misuse of update_mmu_cache() in do_anonymous_page()
2022-09-25 1:43 ` Muchun Song
@ 2022-09-26 8:32 ` David Hildenbrand
2022-09-26 8:41 ` Qi Zheng
0 siblings, 1 reply; 6+ messages in thread
From: David Hildenbrand @ 2022-09-26 8:32 UTC (permalink / raw)
To: Muchun Song, Qi Zheng
Cc: Andrew Morton, Linux MM, linux-kernel, chris, jcmvbkbc, maobibo
On 25.09.22 03:43, Muchun Song wrote:
>
>
>> On Sep 24, 2022, at 13:32, Qi Zheng <zhengqi.arch@bytedance.com> wrote:
>>
>> As message in commit 7df676974359 ("mm/memory.c: Update local TLB
>> if PTE entry exists") said, we should update local TLB only on the
>> second thread. So fix the misuse of update_mmu_cache() by using
>> update_mmu_tlb() in the do_anonymous_page().
>>
>> Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
>
> The change looks good to me. However, I am not sure what is the user-visible
> effect to xtensa users. So Cc xtensa’s maintainer and the author of 7df676974359
> to double check this.
And if there is one, do we have a fixes tag?
--
Thanks,
David / dhildenb
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] mm: fix misuse of update_mmu_cache() in do_anonymous_page()
2022-09-26 8:32 ` David Hildenbrand
@ 2022-09-26 8:41 ` Qi Zheng
2022-09-26 8:42 ` David Hildenbrand
0 siblings, 1 reply; 6+ messages in thread
From: Qi Zheng @ 2022-09-26 8:41 UTC (permalink / raw)
To: David Hildenbrand, Muchun Song
Cc: Andrew Morton, Linux MM, linux-kernel, chris, jcmvbkbc, maobibo
On 2022/9/26 16:32, David Hildenbrand wrote:
> On 25.09.22 03:43, Muchun Song wrote:
>>
>>
>>> On Sep 24, 2022, at 13:32, Qi Zheng <zhengqi.arch@bytedance.com> wrote:
>>>
>>> As message in commit 7df676974359 ("mm/memory.c: Update local TLB
>>> if PTE entry exists") said, we should update local TLB only on the
>>> second thread. So fix the misuse of update_mmu_cache() by using
>>> update_mmu_tlb() in the do_anonymous_page().
>>>
>>> Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
>>
>> The change looks good to me. However, I am not sure what is the
>> user-visible
>> effect to xtensa users. So Cc xtensa’s maintainer and the author of
>> 7df676974359
>> to double check this.
>
> And if there is one, do we have a fixes tag?
IIUC, there's only a performance difference here, so maybe there's no
need to add the fixes tag?
>
--
Thanks,
Qi
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] mm: fix misuse of update_mmu_cache() in do_anonymous_page()
2022-09-26 8:41 ` Qi Zheng
@ 2022-09-26 8:42 ` David Hildenbrand
2022-09-26 8:47 ` Qi Zheng
0 siblings, 1 reply; 6+ messages in thread
From: David Hildenbrand @ 2022-09-26 8:42 UTC (permalink / raw)
To: Qi Zheng, Muchun Song
Cc: Andrew Morton, Linux MM, linux-kernel, chris, jcmvbkbc, maobibo
On 26.09.22 10:41, Qi Zheng wrote:
>
>
> On 2022/9/26 16:32, David Hildenbrand wrote:
>> On 25.09.22 03:43, Muchun Song wrote:
>>>
>>>
>>>> On Sep 24, 2022, at 13:32, Qi Zheng <zhengqi.arch@bytedance.com> wrote:
>>>>
>>>> As message in commit 7df676974359 ("mm/memory.c: Update local TLB
>>>> if PTE entry exists") said, we should update local TLB only on the
>>>> second thread. So fix the misuse of update_mmu_cache() by using
>>>> update_mmu_tlb() in the do_anonymous_page().
>>>>
>>>> Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
>>>
>>> The change looks good to me. However, I am not sure what is the
>>> user-visible
>>> effect to xtensa users. So Cc xtensa’s maintainer and the author of
>>> 7df676974359
>>> to double check this.
>>
>> And if there is one, do we have a fixes tag?
>
> IIUC, there's only a performance difference here, so maybe there's no
> need to add the fixes tag?
Maybe be careful with the usage of "fix" in subject/description then and
point that out in the description :)
--
Thanks,
David / dhildenb
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] mm: fix misuse of update_mmu_cache() in do_anonymous_page()
2022-09-26 8:42 ` David Hildenbrand
@ 2022-09-26 8:47 ` Qi Zheng
0 siblings, 0 replies; 6+ messages in thread
From: Qi Zheng @ 2022-09-26 8:47 UTC (permalink / raw)
To: David Hildenbrand, Muchun Song
Cc: Andrew Morton, Linux MM, linux-kernel, chris, jcmvbkbc, maobibo
On 2022/9/26 16:42, David Hildenbrand wrote:
> On 26.09.22 10:41, Qi Zheng wrote:
>>
>>
>> On 2022/9/26 16:32, David Hildenbrand wrote:
>>> On 25.09.22 03:43, Muchun Song wrote:
>>>>
>>>>
>>>>> On Sep 24, 2022, at 13:32, Qi Zheng <zhengqi.arch@bytedance.com>
>>>>> wrote:
>>>>>
>>>>> As message in commit 7df676974359 ("mm/memory.c: Update local TLB
>>>>> if PTE entry exists") said, we should update local TLB only on the
>>>>> second thread. So fix the misuse of update_mmu_cache() by using
>>>>> update_mmu_tlb() in the do_anonymous_page().
>>>>>
>>>>> Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
>>>>
>>>> The change looks good to me. However, I am not sure what is the
>>>> user-visible
>>>> effect to xtensa users. So Cc xtensa’s maintainer and the author of
>>>> 7df676974359
>>>> to double check this.
>>>
>>> And if there is one, do we have a fixes tag?
>>
>> IIUC, there's only a performance difference here, so maybe there's no
>> need to add the fixes tag?
>
> Maybe be careful with the usage of "fix" in subject/description then and
> point that out in the description :)
Ah, will change subject/description in the v2, thanks. :)
>
--
Thanks,
Qi
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2022-09-26 8:48 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-09-24 5:32 [PATCH] mm: fix misuse of update_mmu_cache() in do_anonymous_page() Qi Zheng
2022-09-25 1:43 ` Muchun Song
2022-09-26 8:32 ` David Hildenbrand
2022-09-26 8:41 ` Qi Zheng
2022-09-26 8:42 ` David Hildenbrand
2022-09-26 8:47 ` Qi Zheng
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