From: Michael Ellerman <patch-notifications@ellerman•id.au>
To: "Aneesh Kumar K.V" <aneesh.kumar@linux•ibm.com>,
npiggin@gmail•com, paulus@samba•org
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux•ibm.com>,
linuxppc-dev@lists•ozlabs.org
Subject: Re: [PATCH v1 1/3] mm/powerpc/book3s64/radix: Remove unused code.
Date: Thu, 14 Nov 2019 20:07:59 +1100 (AEDT) [thread overview]
Message-ID: <47DFxq68zfz9sRR@ozlabs.org> (raw)
In-Reply-To: <20191024075801.22434-1-aneesh.kumar@linux.ibm.com>
On Thu, 2019-10-24 at 07:57:59 UTC, "Aneesh Kumar K.V" wrote:
> mm_tlb_flush_nested change was added in the mmu gather tlb flush to handle
> the case of parallel pte invalidate happening with mmap_sem held in read
> mode. This fix was done by commit: 02390f66bd23 ("powerpc/64s/radix: Fix
> MADV_[FREE|DONTNEED] TLB flush miss problem with THP") and the problem is
> explained in detail in commit: 99baac21e458 ("mm: fix MADV_[FREE|DONTNEED] TLB
> flush miss problem")
>
> This was later updated by commit: 7a30df49f63a ("mm: mmu_gather: remove
> __tlb_reset_range() for force flush") to do a full mm flush rather than
> a range flush. By commit: dd2283f2605e ("mm: mmap: zap pages with read mmap_sem
> in munmap") we are also now allowing a page table free in mmap_sem read mode
> which means we should do a PWC flush too. Our current full mm flush imply
> a PWC flush.
>
> With all the above change the mm_tlb_flush_nested(mm) branch in radix__tlb_flush
> will never be taken because for the nested case we would have taken the
> if (tlb->fullmm) branch. This patch removes the unused code. Also, remove the
> gflush change in __radix__flush_tlb_range that was added to handle the range tlb
> flush code. We only check for THP there because hugetlb is flushed via a
> different code path where page size is explicitly specified
>
> This is a partial revert of commit: 02390f66bd23 ("powerpc/64s/radix: Fix
> MADV_[FREE|DONTNEED] TLB flush miss problem with THP")
>
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux•ibm.com>
Series applied to powerpc next, thanks.
https://git.kernel.org/powerpc/c/a42d6ba8c5be5aa597d25dbc15e336a2eca40260
cheers
prev parent reply other threads:[~2019-11-14 9:52 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-24 7:57 [PATCH v1 1/3] mm/powerpc/book3s64/radix: Remove unused code Aneesh Kumar K.V
2019-10-24 7:58 ` [PATCH v1 2/3] powerpc/mm/book3s64/radix: Use freed_tables instead of need_flush_all Aneesh Kumar K.V
2019-10-24 7:58 ` [PATCH v1 3/3] powerpc/mm/book3s64/radix: Flush the full mm even when need_flush_all is set Aneesh Kumar K.V
2019-11-14 9:07 ` Michael Ellerman [this message]
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