From: Peter Xu <peterx@redhat.com> To: linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>, peterx@redhat.com, Andrew Morton <akpm@linux-foundation.org>, Andrea Arcangeli <aarcange@redhat.com>, Will Deacon <will@kernel.org>, Michael Ellerman <mpe@ellerman.id.au>, Linus Torvalds <torvalds@linux-foundation.org>, Russell King <linux@armlinux.org.uk>, linux-arm-kernel@lists.infradead.org Subject: [PATCH 04/26] mm/arm: Use general page fault accounting Date: Fri, 19 Jun 2020 12:05:16 -0400 [thread overview] Message-ID: <20200619160538.8641-5-peterx@redhat.com> (raw) In-Reply-To: <20200619160538.8641-1-peterx@redhat.com> Use the general page fault accounting by passing regs into handle_mm_fault(). It naturally solve the issue of multiple page fault accounting when page fault retry happened. To do this, we need to pass the pt_regs pointer into __do_page_fault(). Fix PERF_COUNT_SW_PAGE_FAULTS perf event manually for page fault retries, by moving it before taking mmap_sem. CC: Russell King <linux@armlinux.org.uk> CC: Will Deacon <will@kernel.org> CC: linux-arm-kernel@lists.infradead.org Signed-off-by: Peter Xu <peterx@redhat.com> --- arch/arm/mm/fault.c | 25 ++++++------------------- 1 file changed, 6 insertions(+), 19 deletions(-) diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c index 0d6be0f4f27c..8530befee012 100644 --- a/arch/arm/mm/fault.c +++ b/arch/arm/mm/fault.c @@ -201,7 +201,8 @@ static inline bool access_error(unsigned int fsr, struct vm_area_struct *vma) static vm_fault_t __kprobes __do_page_fault(struct mm_struct *mm, unsigned long addr, unsigned int fsr, - unsigned int flags, struct task_struct *tsk) + unsigned int flags, struct task_struct *tsk, + struct pt_regs *regs) { struct vm_area_struct *vma; vm_fault_t fault; @@ -223,7 +224,7 @@ __do_page_fault(struct mm_struct *mm, unsigned long addr, unsigned int fsr, goto out; } - return handle_mm_fault(vma, addr & PAGE_MASK, flags, NULL); + return handle_mm_fault(vma, addr & PAGE_MASK, flags, regs); check_stack: /* Don't allow expansion below FIRST_USER_ADDRESS */ @@ -265,6 +266,8 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) if ((fsr & FSR_WRITE) && !(fsr & FSR_CM)) flags |= FAULT_FLAG_WRITE; + perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr); + /* * As per x86, we may deadlock here. However, since the kernel only * validly references user space from well defined areas of the code, @@ -289,7 +292,7 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) #endif } - fault = __do_page_fault(mm, addr, fsr, flags, tsk); + fault = __do_page_fault(mm, addr, fsr, flags, tsk, regs); /* If we need to retry but a fatal signal is pending, handle the * signal first. We do not need to release the mmap_sem because @@ -301,23 +304,7 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) return 0; } - /* - * Major/minor page fault accounting is only done on the - * initial attempt. If we go through a retry, it is extremely - * likely that the page will be found in page cache at that point. - */ - - perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr); if (!(fault & VM_FAULT_ERROR) && flags & FAULT_FLAG_ALLOW_RETRY) { - if (fault & VM_FAULT_MAJOR) { - tsk->maj_flt++; - perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, - regs, addr); - } else { - tsk->min_flt++; - perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, - regs, addr); - } if (fault & VM_FAULT_RETRY) { flags |= FAULT_FLAG_TRIED; goto retry; -- 2.26.2
WARNING: multiple messages have this Message-ID (diff)
From: Peter Xu <peterx@redhat.com> To: linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: Andrea Arcangeli <aarcange@redhat.com>, Michael Ellerman <mpe@ellerman.id.au>, Russell King <linux@armlinux.org.uk>, peterx@redhat.com, Linus Torvalds <torvalds@linux-foundation.org>, linux-arm-kernel@lists.infradead.org, Andrew Morton <akpm@linux-foundation.org>, Will Deacon <will@kernel.org>, Gerald Schaefer <gerald.schaefer@de.ibm.com> Subject: [PATCH 04/26] mm/arm: Use general page fault accounting Date: Fri, 19 Jun 2020 12:05:16 -0400 [thread overview] Message-ID: <20200619160538.8641-5-peterx@redhat.com> (raw) In-Reply-To: <20200619160538.8641-1-peterx@redhat.com> Use the general page fault accounting by passing regs into handle_mm_fault(). It naturally solve the issue of multiple page fault accounting when page fault retry happened. To do this, we need to pass the pt_regs pointer into __do_page_fault(). Fix PERF_COUNT_SW_PAGE_FAULTS perf event manually for page fault retries, by moving it before taking mmap_sem. CC: Russell King <linux@armlinux.org.uk> CC: Will Deacon <will@kernel.org> CC: linux-arm-kernel@lists.infradead.org Signed-off-by: Peter Xu <peterx@redhat.com> --- arch/arm/mm/fault.c | 25 ++++++------------------- 1 file changed, 6 insertions(+), 19 deletions(-) diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c index 0d6be0f4f27c..8530befee012 100644 --- a/arch/arm/mm/fault.c +++ b/arch/arm/mm/fault.c @@ -201,7 +201,8 @@ static inline bool access_error(unsigned int fsr, struct vm_area_struct *vma) static vm_fault_t __kprobes __do_page_fault(struct mm_struct *mm, unsigned long addr, unsigned int fsr, - unsigned int flags, struct task_struct *tsk) + unsigned int flags, struct task_struct *tsk, + struct pt_regs *regs) { struct vm_area_struct *vma; vm_fault_t fault; @@ -223,7 +224,7 @@ __do_page_fault(struct mm_struct *mm, unsigned long addr, unsigned int fsr, goto out; } - return handle_mm_fault(vma, addr & PAGE_MASK, flags, NULL); + return handle_mm_fault(vma, addr & PAGE_MASK, flags, regs); check_stack: /* Don't allow expansion below FIRST_USER_ADDRESS */ @@ -265,6 +266,8 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) if ((fsr & FSR_WRITE) && !(fsr & FSR_CM)) flags |= FAULT_FLAG_WRITE; + perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr); + /* * As per x86, we may deadlock here. However, since the kernel only * validly references user space from well defined areas of the code, @@ -289,7 +292,7 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) #endif } - fault = __do_page_fault(mm, addr, fsr, flags, tsk); + fault = __do_page_fault(mm, addr, fsr, flags, tsk, regs); /* If we need to retry but a fatal signal is pending, handle the * signal first. We do not need to release the mmap_sem because @@ -301,23 +304,7 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) return 0; } - /* - * Major/minor page fault accounting is only done on the - * initial attempt. If we go through a retry, it is extremely - * likely that the page will be found in page cache at that point. - */ - - perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr); if (!(fault & VM_FAULT_ERROR) && flags & FAULT_FLAG_ALLOW_RETRY) { - if (fault & VM_FAULT_MAJOR) { - tsk->maj_flt++; - perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, - regs, addr); - } else { - tsk->min_flt++; - perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, - regs, addr); - } if (fault & VM_FAULT_RETRY) { flags |= FAULT_FLAG_TRIED; goto retry; -- 2.26.2 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2020-06-19 16:07 UTC|newest] Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-06-19 16:05 [PATCH 00/26] mm: Page fault accounting cleanups Peter Xu 2020-06-19 16:05 ` [PATCH 01/26] mm: Do page fault accounting in handle_mm_fault Peter Xu 2020-06-24 18:49 ` Gerald Schaefer 2020-06-24 20:34 ` Peter Xu 2020-06-26 19:54 ` Gerald Schaefer 2020-06-26 21:53 ` Peter Xu 2020-06-26 22:27 ` Peter Xu 2020-06-19 16:05 ` [PATCH 02/26] mm/alpha: Use general page fault accounting Peter Xu 2020-06-19 16:05 ` [PATCH 03/26] mm/arc: " Peter Xu 2020-06-19 16:05 ` Peter Xu 2020-06-19 16:05 ` Peter Xu [this message] 2020-06-19 16:05 ` [PATCH 04/26] mm/arm: " Peter Xu 2020-06-19 16:05 ` [PATCH 05/26] mm/arm64: " Peter Xu 2020-06-19 16:05 ` Peter Xu 2020-06-19 16:05 ` [PATCH 06/26] mm/csky: " Peter Xu 2020-06-20 1:44 ` Guo Ren 2020-06-20 1:44 ` Guo Ren 2020-06-20 16:08 ` Peter Xu 2020-06-19 16:05 ` [PATCH 07/26] mm/hexagon: " Peter Xu 2020-06-19 16:05 ` [PATCH 08/26] mm/ia64: " Peter Xu 2020-06-19 16:05 ` [PATCH 09/26] mm/m68k: " Peter Xu 2020-06-19 16:05 ` [PATCH 10/26] mm/microblaze: " Peter Xu 2020-06-19 16:05 ` [PATCH 11/26] mm/mips: " Peter Xu 2020-06-25 8:28 ` Thomas Bogendoerfer 2020-06-19 16:05 ` [PATCH 12/26] mm/nds32: " Peter Xu 2020-06-19 16:12 ` [PATCH 13/26] mm/nios2: " Peter Xu 2020-06-19 16:12 ` [PATCH 14/26] mm/openrisc: " Peter Xu 2020-06-19 16:12 ` [OpenRISC] " Peter Xu 2020-06-19 16:13 ` [PATCH 15/26] mm/parisc: " Peter Xu 2020-06-19 16:13 ` [PATCH 16/26] mm/powerpc: " Peter Xu 2020-06-19 16:13 ` Peter Xu 2020-06-19 16:13 ` [PATCH 17/26] mm/riscv: " Peter Xu 2020-06-19 16:13 ` Peter Xu 2020-06-19 16:13 ` [PATCH 18/26] mm/s390: " Peter Xu 2020-06-24 18:49 ` Gerald Schaefer 2020-06-24 20:40 ` Peter Xu 2020-06-19 16:13 ` [PATCH 19/26] mm/sh: " Peter Xu 2020-06-19 16:13 ` Peter Xu 2020-06-19 16:13 ` [PATCH 20/26] mm/sparc32: " Peter Xu 2020-06-19 16:13 ` Peter Xu 2020-06-19 16:13 ` [PATCH 21/26] mm/sparc64: " Peter Xu 2020-06-19 16:13 ` Peter Xu 2020-06-19 16:13 ` [PATCH 22/26] mm/unicore32: " Peter Xu 2020-06-19 16:13 ` [PATCH 23/26] mm/x86: " Peter Xu 2020-06-19 16:13 ` [PATCH 24/26] mm/xtensa: " Peter Xu 2020-06-19 16:14 ` [PATCH 25/26] mm: Clean up the last pieces of page fault accountings Peter Xu 2020-06-19 16:14 ` [PATCH 26/26] mm/gup: Remove task_struct pointer for all gup code Peter Xu 2020-06-26 22:31 [PATCH 00/26] mm: Page fault accounting cleanups Peter Xu 2020-06-26 22:31 ` [PATCH 04/26] mm/arm: Use general page fault accounting Peter Xu 2020-06-26 22:31 ` Peter Xu
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