Re: [PATCH] powerpc/book3s64/radix/tlb: Determine hugepage flush correctly
On Wed, 13 May 2020 08:36:16 +0530, Aneesh Kumar K.V wrote: > With a 64K page size flush with start and end value as below > (start, end) = (721f680d, 721f680e) results in > (hstart, hend) = (721f6820, 721f6800) > > Avoid doing a __tlbie_va_range with the wrong hstart and hend value in this > case. > > [...] Applied to powerpc/next. [1/1] powerpc/book3s64/radix/tlb: Determine hugepage flush correctly https://git.kernel.org/powerpc/c/8f53f9c0f68ab2168f637494b9e24034899c1310 cheers
Re: [PATCH] powerpc/book3s64/radix/tlb: Determine hugepage flush correctly
Nicholas Piggin writes:
> Excerpts from Aneesh Kumar K.V's message of May 13, 2020 1:06 pm:
>> With a 64K page size flush with start and end value as below
>> (start, end) = (721f680d, 721f680e) results in
>> (hstart, hend) = (721f6820, 721f6800)
>>
>> Avoid doing a __tlbie_va_range with the wrong hstart and hend value in this
>> case.
>>
>> __tlbie_va_range will skip the actual tlbie operation for start > end.
>> But we still end up doing the tlbie fixup.
>
> Hm, good catch.
>
>> Reported-by: Bharata B Rao
>> Signed-off-by: Aneesh Kumar K.V
>> ---
>> arch/powerpc/mm/book3s64/radix_tlb.c | 6 +++---
>> 1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/arch/powerpc/mm/book3s64/radix_tlb.c
>> b/arch/powerpc/mm/book3s64/radix_tlb.c
>> index 758ade2c2b6e..d592f9e1c037 100644
>> --- a/arch/powerpc/mm/book3s64/radix_tlb.c
>> +++ b/arch/powerpc/mm/book3s64/radix_tlb.c
>> @@ -884,10 +884,10 @@ static inline void __radix__flush_tlb_range(struct
>> mm_struct *mm,
>> if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) {
>> hstart = (start + PMD_SIZE - 1) & PMD_MASK;
>> hend = end & PMD_MASK;
>> -if (hstart == hend)
>> -hflush = false;
>> -else
>> +if (hstart < hend)
>> hflush = true;
>> +else
>> +hflush = false;
>
> We can probably get rid of the else part since it is already false.
Yeah I can do that when applying.
cheers
Re: [PATCH] powerpc/book3s64/radix/tlb: Determine hugepage flush correctly
Excerpts from Aneesh Kumar K.V's message of May 13, 2020 1:06 pm:
> With a 64K page size flush with start and end value as below
> (start, end) = (721f680d, 721f680e) results in
> (hstart, hend) = (721f6820, 721f6800)
>
> Avoid doing a __tlbie_va_range with the wrong hstart and hend value in this
> case.
>
> __tlbie_va_range will skip the actual tlbie operation for start > end.
> But we still end up doing the tlbie fixup.
Hm, good catch.
> Reported-by: Bharata B Rao
> Signed-off-by: Aneesh Kumar K.V
> ---
> arch/powerpc/mm/book3s64/radix_tlb.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/arch/powerpc/mm/book3s64/radix_tlb.c
> b/arch/powerpc/mm/book3s64/radix_tlb.c
> index 758ade2c2b6e..d592f9e1c037 100644
> --- a/arch/powerpc/mm/book3s64/radix_tlb.c
> +++ b/arch/powerpc/mm/book3s64/radix_tlb.c
> @@ -884,10 +884,10 @@ static inline void __radix__flush_tlb_range(struct
> mm_struct *mm,
> if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) {
> hstart = (start + PMD_SIZE - 1) & PMD_MASK;
> hend = end & PMD_MASK;
> - if (hstart == hend)
> - hflush = false;
> - else
> + if (hstart < hend)
> hflush = true;
> + else
> + hflush = false;
We can probably get rid of the else part since it is already false.
Otherwise
Reviewed-by: Nicholas Piggin
[PATCH] powerpc/book3s64/radix/tlb: Determine hugepage flush correctly
With a 64K page size flush with start and end value as below
(start, end) = (721f680d, 721f680e) results in
(hstart, hend) = (721f6820, 721f6800)
Avoid doing a __tlbie_va_range with the wrong hstart and hend value in this
case.
__tlbie_va_range will skip the actual tlbie operation for start > end.
But we still end up doing the tlbie fixup.
Reported-by: Bharata B Rao
Signed-off-by: Aneesh Kumar K.V
---
arch/powerpc/mm/book3s64/radix_tlb.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/mm/book3s64/radix_tlb.c
b/arch/powerpc/mm/book3s64/radix_tlb.c
index 758ade2c2b6e..d592f9e1c037 100644
--- a/arch/powerpc/mm/book3s64/radix_tlb.c
+++ b/arch/powerpc/mm/book3s64/radix_tlb.c
@@ -884,10 +884,10 @@ static inline void __radix__flush_tlb_range(struct
mm_struct *mm,
if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) {
hstart = (start + PMD_SIZE - 1) & PMD_MASK;
hend = end & PMD_MASK;
- if (hstart == hend)
- hflush = false;
- else
+ if (hstart < hend)
hflush = true;
+ else
+ hflush = false;
}
if (local) {
--
2.26.2
