From: mlangsdo@redhat•com (Mark Langsdorf)
To: linux-arm-kernel@lists•infradead.org
Subject: Linux 3.19-rc3
Date: Mon, 12 Jan 2015 07:22:22 -0600 [thread overview]
Message-ID: <54B3CA8E.8050100@redhat.com> (raw)
In-Reply-To: <20150112124256.GB13360@arm.com>
On 01/12/2015 06:42 AM, Will Deacon wrote:
> On Sat, Jan 10, 2015 at 07:51:03PM +0000, Linus Torvalds wrote:
>> I can revert the commit that causes problems, but considering the
>> performance impact on x86 (it would be a regression since 3.18), I
>> would *really* like to fix the arm64 problem instead. So I'll wait
>> with the revert for at least a week, I think, hoping that the arm64
>> people figure this out. Sound reasonable?
>
> Sure. I've put together the following patch which:
>
> (1) Uses tlb->end != 0 only as the predicate for TLB invalidation
>
> (2) Uses tlb->local.nr as the predicate for page freeing in
> tlb_flush_mmu_free
>
> (3) Ensures tlb->end != 0 for the fullmm case (I think this was a
> benign change introduced by my original patch, but this puts us
> back to 3.18 behaviour)
>
> Since this effectively reverts f045bbb9fa1b, I've added Dave to Cc. It
> should fix the leak without reintroducing the performance regression.
>
> Linus: this moves the tlb->end check back into tlb_flush_mmu_tlbonly.
> How much do you hate that?
>
> diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h
> index 08848050922e..db284bff29dc 100644
> --- a/include/asm-generic/tlb.h
> +++ b/include/asm-generic/tlb.h
> @@ -136,8 +136,12 @@ static inline void __tlb_adjust_range(struct mmu_gather *tlb,
>
> static inline void __tlb_reset_range(struct mmu_gather *tlb)
> {
> - tlb->start = TASK_SIZE;
> - tlb->end = 0;
> + if (tlb->fullmm) {
> + tlb->start = tlb->end = ~0;
> + } else {
> + tlb->start = TASK_SIZE;
> + tlb->end = 0;
> + }
> }
>
> /*
> diff --git a/mm/memory.c b/mm/memory.c
> index c6565f00fb38..54f3a9b00956 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -235,6 +235,9 @@ void tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, unsigned long
>
> static void tlb_flush_mmu_tlbonly(struct mmu_gather *tlb)
> {
> + if (!tlb->end)
> + return;
> +
> tlb_flush(tlb);
> mmu_notifier_invalidate_range(tlb->mm, tlb->start, tlb->end);
> #ifdef CONFIG_HAVE_RCU_TABLE_FREE
> @@ -247,7 +250,7 @@ static void tlb_flush_mmu_free(struct mmu_gather *tlb)
> {
> struct mmu_gather_batch *batch;
>
> - for (batch = &tlb->local; batch; batch = batch->next) {
> + for (batch = &tlb->local; batch && batch->nr; batch = batch->next) {
> free_pages_and_swap_cache(batch->pages, batch->nr);
> batch->nr = 0;
> }
> @@ -256,9 +259,6 @@ static void tlb_flush_mmu_free(struct mmu_gather *tlb)
>
> void tlb_flush_mmu(struct mmu_gather *tlb)
> {
> - if (!tlb->end)
> - return;
> -
> tlb_flush_mmu_tlbonly(tlb);
> tlb_flush_mmu_free(tlb);
> }
>
This fixes the originally reported problem. I have no opinion on
moving the tlb->end check back into tlb_flush_mmu_tlbonly.
Tested-by: Mark Langsdorf <mlangsdo@redhat•com>
next prev parent reply other threads:[~2015-01-12 13:22 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CA+55aFwsxoyLb9OWMSCL3doe_cz_EQtKsEFCyPUYn_T87pbz0A@mail.gmail.com>
2015-01-08 12:51 ` Linux 3.19-rc3 Mark Langsdorf
2015-01-08 13:45 ` Catalin Marinas
2015-01-08 17:29 ` Mark Langsdorf
2015-01-08 17:34 ` Catalin Marinas
2015-01-08 18:48 ` Mark Langsdorf
2015-01-08 19:21 ` Linus Torvalds
2015-01-09 23:27 ` Catalin Marinas
2015-01-10 0:35 ` Kirill A. Shutemov
2015-01-10 2:27 ` Linus Torvalds
2015-01-10 2:51 ` David Lang
2015-01-10 3:06 ` Linus Torvalds
2015-01-10 10:46 ` Andreas Mohr
2015-01-10 19:42 ` Linus Torvalds
2015-01-13 3:33 ` Rik van Riel
2015-01-13 10:28 ` Catalin Marinas
2015-01-10 3:17 ` Tony Luck
2015-01-10 20:16 ` Arnd Bergmann
2015-01-10 21:00 ` Linus Torvalds
2015-01-10 21:36 ` Arnd Bergmann
2015-01-10 21:48 ` Linus Torvalds
2015-01-12 11:37 ` Kirill A. Shutemov
2015-01-12 12:18 ` Catalin Marinas
2015-01-12 13:57 ` Arnd Bergmann
2015-01-12 14:23 ` Catalin Marinas
2015-01-12 15:42 ` Arnd Bergmann
2015-01-12 11:53 ` Catalin Marinas
2015-01-12 13:15 ` Arnd Bergmann
2015-01-08 15:08 ` Michal Hocko
2015-01-08 16:37 ` Mark Langsdorf
2015-01-09 15:56 ` Michal Hocko
2015-01-09 12:13 ` Mark Rutland
2015-01-09 14:19 ` Steve Capper
2015-01-09 14:27 ` Mark Langsdorf
2015-01-09 17:57 ` Mark Rutland
2015-01-09 18:37 ` Marc Zyngier
2015-01-09 19:43 ` Will Deacon
2015-01-10 3:29 ` Laszlo Ersek
2015-01-10 4:39 ` Linus Torvalds
2015-01-10 13:37 ` Will Deacon
2015-01-10 19:47 ` Laszlo Ersek
2015-01-10 19:56 ` Linus Torvalds
2015-01-10 20:08 ` Laszlo Ersek
2015-01-10 19:51 ` Linus Torvalds
2015-01-12 12:42 ` Will Deacon
2015-01-12 13:22 ` Mark Langsdorf [this message]
2015-01-12 19:03 ` Dave Hansen
2015-01-12 19:06 ` Linus Torvalds
2015-01-12 19:07 ` Linus Torvalds
2015-01-12 19:24 ` Will Deacon
2015-01-10 15:22 ` Kyle McMartin
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