From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758857Ab2KVWvk (ORCPT ); Thu, 22 Nov 2012 17:51:40 -0500 Received: from mail-ee0-f46.google.com ([74.125.83.46]:42291 "EHLO mail-ee0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932746Ab2KVWvZ (ORCPT ); Thu, 22 Nov 2012 17:51:25 -0500 From: Ingo Molnar To: linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: Peter Zijlstra , Paul Turner , Lee Schermerhorn , Christoph Lameter , Rik van Riel , Mel Gorman , Andrew Morton , Andrea Arcangeli , Linus Torvalds , Thomas Gleixner , Johannes Weiner , Hugh Dickins Subject: [PATCH 21/33] sched, numa, mm: Count WS scanning against present PTEs, not virtual memory ranges Date: Thu, 22 Nov 2012 23:49:42 +0100 Message-Id: <1353624594-1118-22-git-send-email-mingo@kernel.org> X-Mailer: git-send-email 1.7.11.7 In-Reply-To: <1353624594-1118-1-git-send-email-mingo@kernel.org> References: <1353624594-1118-1-git-send-email-mingo@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Peter Zijlstra By accounting against the present PTEs, scanning speed reflects the actual present (mapped) memory. Suggested-by: Ingo Molnar Signed-off-by: Peter Zijlstra Cc: Linus Torvalds Cc: Andrew Morton Cc: Andrea Arcangeli Cc: Rik van Riel Cc: Mel Gorman Cc: Hugh Dickins Signed-off-by: Ingo Molnar --- kernel/sched/fair.c | 37 +++++++++++++++++++++---------------- 1 file changed, 21 insertions(+), 16 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 151a3cd..da28315 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -914,8 +914,8 @@ void task_numa_work(struct callback_head *work) struct task_struct *p = current; struct mm_struct *mm = p->mm; struct vm_area_struct *vma; - unsigned long offset, end; - long length; + unsigned long start, end; + long pages; WARN_ON_ONCE(p != container_of(work, struct task_struct, numa_work)); @@ -942,30 +942,35 @@ void task_numa_work(struct callback_head *work) if (cmpxchg(&mm->numa_next_scan, migrate, next_scan) != migrate) return; - offset = mm->numa_scan_offset; - length = sysctl_sched_numa_scan_size; - length <<= 20; + start = mm->numa_scan_offset; + pages = sysctl_sched_numa_scan_size; + pages <<= 20 - PAGE_SHIFT; /* MB in pages */ + if (!pages) + return; down_write(&mm->mmap_sem); - vma = find_vma(mm, offset); + vma = find_vma(mm, start); if (!vma) { ACCESS_ONCE(mm->numa_scan_seq)++; - offset = 0; + start = 0; vma = mm->mmap; } - for (; vma && length > 0; vma = vma->vm_next) { + for (; vma; vma = vma->vm_next) { if (!vma_migratable(vma)) continue; - offset = max(offset, vma->vm_start); - end = min(ALIGN(offset + length, HPAGE_SIZE), vma->vm_end); - length -= end - offset; - - change_prot_numa(vma, offset, end); - - offset = end; + do { + start = max(start, vma->vm_start); + end = ALIGN(start + (pages << PAGE_SHIFT), HPAGE_SIZE); + end = min(end, vma->vm_end); + pages -= change_prot_numa(vma, start, end); + start = end; + if (pages <= 0) + goto out; + } while (end != vma->vm_end); } - mm->numa_scan_offset = offset; +out: + mm->numa_scan_offset = start; up_write(&mm->mmap_sem); } -- 1.7.11.7