mm/xtensa: use general page fault accounting (484e51e4) · Commits · 戴 / test

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. Remove the PERF_COUNT_SW_PAGE_FAULTS_[MAJ|MIN] perf events because it's now also done in handle_mm_fault(). Move the PERF_COUNT_SW_PAGE_FAULTS event higher before taking mmap_sem for the fault, then it'll match with the rest of the archs. Signed-off-by:

Peter Xu <peterx@redhat.com> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Acked-by:

Max Filippov <jcmvbkbc@gmail.com> Cc: Chris Zankel <chris@zankel.net> Link: http://lkml.kernel.org/r/20200707225021.200906-24-peterx@redhat.com Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

arch/xtensa/mm/fault.c

+4 −11

Original line number	Diff line number	Diff line
		@@ -72,6 +72,9 @@ void do_page_fault(struct pt_regs *regs)

		if (user_mode(regs))
		flags \|= FAULT_FLAG_USER;

		perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);

		retry:
		mmap_read_lock(mm);
		vma = find_vma(mm, address);
		@@ -107,7 +110,7 @@ good_area:
		* make sure we exit gracefully rather than endlessly redo
		* the fault.
		*/
		fault = handle_mm_fault(vma, address, flags, NULL);
		fault = handle_mm_fault(vma, address, flags, regs);

		if (fault_signal_pending(fault, regs))
		return;
		@@ -122,10 +125,6 @@ good_area:
		BUG();
		}
		if (flags & FAULT_FLAG_ALLOW_RETRY) {
		if (fault & VM_FAULT_MAJOR)
		current->maj_flt++;
		else
		current->min_flt++;
		if (fault & VM_FAULT_RETRY) {
		flags \|= FAULT_FLAG_TRIED;

		@@ -139,12 +138,6 @@ good_area:
		}

		mmap_read_unlock(mm);
		perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
		if (flags & VM_FAULT_MAJOR)
		perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, regs, address);
		else
		perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, regs, address);

		return;

		/* Something tried to access memory that isn't in our memory map..

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