From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: Re: [RFC PATCH v5 4/8] mm: tlb: Pass struct mmu_gather to flush_pmd_tlb_range Date: Tue, 31 Mar 2020 17:13:31 +0200 Message-ID: <20200331151331.GS20730@hirez.programming.kicks-ass.net> References: <20200331142927.1237-1-yezhenyu2@huawei.com> <20200331142927.1237-5-yezhenyu2@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from merlin.infradead.org ([205.233.59.134]:48556 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730466AbgCaPO1 (ORCPT ); Tue, 31 Mar 2020 11:14:27 -0400 Content-Disposition: inline In-Reply-To: <20200331142927.1237-5-yezhenyu2@huawei.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Zhenyu Ye Cc: mark.rutland@arm.com, will@kernel.org, catalin.marinas@arm.com, aneesh.kumar@linux.ibm.com, akpm@linux-foundation.org, npiggin@gmail.com, arnd@arndb.de, rostedt@goodmis.org, maz@kernel.org, suzuki.poulose@arm.com, tglx@linutronix.de, yuzhao@google.com, Dave.Martin@arm.com, steven.price@arm.com, broonie@kernel.org, guohanjun@huawei.com, corbet@lwn.net, vgupta@synopsys.com, tony.luck@intel.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, arm@kernel.org, xiexiangyou@huawei.com, prime.zeng@hisilicon.com, zhangshaokun@hisilicon.com, kuhn.chenqun@huawei.com On Tue, Mar 31, 2020 at 10:29:23PM +0800, Zhenyu Ye wrote: > diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h > index e2e2bef07dd2..32d4661e5a56 100644 > --- a/include/asm-generic/pgtable.h > +++ b/include/asm-generic/pgtable.h > @@ -1160,10 +1160,10 @@ static inline int pmd_free_pte_page(pmd_t *pmd, unsigned long addr) > * invalidate the entire TLB which is not desitable. > * e.g. see arch/arc: flush_pmd_tlb_range > */ > -#define flush_pmd_tlb_range(vma, addr, end) flush_tlb_range(vma, addr, end) > +#define flush_pmd_tlb_range(tlb, vma, addr, end) flush_tlb_range(vma, addr, end) > #define flush_pud_tlb_range(vma, addr, end) flush_tlb_range(vma, addr, end) > #else > -#define flush_pmd_tlb_range(vma, addr, end) BUILD_BUG() > +#define flush_pmd_tlb_range(tlb, vma, addr, end) BUILD_BUG() > #define flush_pud_tlb_range(vma, addr, end) BUILD_BUG() > #endif > #endif > diff --git a/mm/pgtable-generic.c b/mm/pgtable-generic.c > index 3d7c01e76efc..96c9cf77bfb5 100644 > --- a/mm/pgtable-generic.c > +++ b/mm/pgtable-generic.c > @@ -109,8 +109,14 @@ int pmdp_set_access_flags(struct vm_area_struct *vma, > int changed = !pmd_same(*pmdp, entry); > VM_BUG_ON(address & ~HPAGE_PMD_MASK); > if (changed) { > + struct mmu_gather tlb; > + unsigned long tlb_start = address; > + unsigned long tlb_end = address + HPAGE_PMD_SIZE; > set_pmd_at(vma->vm_mm, address, pmdp, entry); > - flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE); > + tlb_gather_mmu(&tlb, vma->vm_mm, tlb_start, tlb_end); > + tlb.cleared_pmds = 1; > + flush_pmd_tlb_range(&tlb, vma, tlb_start, tlb_end); > + tlb_finish_mmu(&tlb, tlb_start, tlb_end); > } > return changed; > } This is madness. Please, carefully consider what you just wrote and what it will do in the generic case. Instead of trying to retro-fit flush_*tlb_range() to take an mmu_gather parameter, please replace them out-right. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Tue, 31 Mar 2020 17:13:31 +0200 From: Peter Zijlstra Subject: Re: [RFC PATCH v5 4/8] mm: tlb: Pass struct mmu_gather to flush_pmd_tlb_range Message-ID: <20200331151331.GS20730@hirez.programming.kicks-ass.net> References: <20200331142927.1237-1-yezhenyu2@huawei.com> <20200331142927.1237-5-yezhenyu2@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200331142927.1237-5-yezhenyu2@huawei.com> Sender: owner-linux-mm@kvack.org To: Zhenyu Ye Cc: mark.rutland@arm.com, will@kernel.org, catalin.marinas@arm.com, aneesh.kumar@linux.ibm.com, akpm@linux-foundation.org, npiggin@gmail.com, arnd@arndb.de, rostedt@goodmis.org, maz@kernel.org, suzuki.poulose@arm.com, tglx@linutronix.de, yuzhao@google.com, Dave.Martin@arm.com, steven.price@arm.com, broonie@kernel.org, guohanjun@huawei.com, corbet@lwn.net, vgupta@synopsys.com, tony.luck@intel.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, arm@kernel.org, xiexiangyou@huawei.com, prime.zeng@hisilicon.com, zhangshaokun@hisilicon.com, kuhn.chenqun@huawei.com List-ID: Message-ID: <20200331151331.O6rkiG6kD7WZ7Y5owu2LVTYUFOGpPmbJh3yYxIfPL14@z> On Tue, Mar 31, 2020 at 10:29:23PM +0800, Zhenyu Ye wrote: > diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h > index e2e2bef07dd2..32d4661e5a56 100644 > --- a/include/asm-generic/pgtable.h > +++ b/include/asm-generic/pgtable.h > @@ -1160,10 +1160,10 @@ static inline int pmd_free_pte_page(pmd_t *pmd, unsigned long addr) > * invalidate the entire TLB which is not desitable. > * e.g. see arch/arc: flush_pmd_tlb_range > */ > -#define flush_pmd_tlb_range(vma, addr, end) flush_tlb_range(vma, addr, end) > +#define flush_pmd_tlb_range(tlb, vma, addr, end) flush_tlb_range(vma, addr, end) > #define flush_pud_tlb_range(vma, addr, end) flush_tlb_range(vma, addr, end) > #else > -#define flush_pmd_tlb_range(vma, addr, end) BUILD_BUG() > +#define flush_pmd_tlb_range(tlb, vma, addr, end) BUILD_BUG() > #define flush_pud_tlb_range(vma, addr, end) BUILD_BUG() > #endif > #endif > diff --git a/mm/pgtable-generic.c b/mm/pgtable-generic.c > index 3d7c01e76efc..96c9cf77bfb5 100644 > --- a/mm/pgtable-generic.c > +++ b/mm/pgtable-generic.c > @@ -109,8 +109,14 @@ int pmdp_set_access_flags(struct vm_area_struct *vma, > int changed = !pmd_same(*pmdp, entry); > VM_BUG_ON(address & ~HPAGE_PMD_MASK); > if (changed) { > + struct mmu_gather tlb; > + unsigned long tlb_start = address; > + unsigned long tlb_end = address + HPAGE_PMD_SIZE; > set_pmd_at(vma->vm_mm, address, pmdp, entry); > - flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE); > + tlb_gather_mmu(&tlb, vma->vm_mm, tlb_start, tlb_end); > + tlb.cleared_pmds = 1; > + flush_pmd_tlb_range(&tlb, vma, tlb_start, tlb_end); > + tlb_finish_mmu(&tlb, tlb_start, tlb_end); > } > return changed; > } This is madness. Please, carefully consider what you just wrote and what it will do in the generic case. Instead of trying to retro-fit flush_*tlb_range() to take an mmu_gather parameter, please replace them out-right.