From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933006Ab1KHP3a (ORCPT ); Tue, 8 Nov 2011 10:29:30 -0500 Received: from mx1.redhat.com ([209.132.183.28]:20559 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932946Ab1KHP3Z (ORCPT ); Tue, 8 Nov 2011 10:29:25 -0500 From: Andrea Arcangeli To: "Rafael J. Wysocki" Cc: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Jiri Slaby , linux-mm@kvack.org, Andrew Morton Subject: [PATCH] thp: reduce khugepaged freezing latency Date: Tue, 8 Nov 2011 16:29:11 +0100 Message-Id: <1320766151-2619-2-git-send-email-aarcange@redhat.com> In-Reply-To: <1320766151-2619-1-git-send-email-aarcange@redhat.com> References: <4EB8E969.6010502@suse.cz> <1320766151-2619-1-git-send-email-aarcange@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Lack of set_freezable_with_signal() prevented khugepaged to be waken up (and prevented to sleep again) across the schedule_timeout_interruptible() calls after freezing() becomes true. The tight loop in khugepaged_alloc_hugepage() also missed one try_to_freeze() call in case alloc_hugepage() would repeatedly fail in turn preventing the loop to break and to reach the try_to_freeze() in the khugepaged main loop. khugepaged would still freeze just fine by trying again the next minute but it's better if it freezes immediately. Reported-by: Jiri Slaby Signed-off-by: Andrea Arcangeli --- mm/huge_memory.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 4298aba..67311d1 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2277,6 +2277,7 @@ static struct page *khugepaged_alloc_hugepage(void) if (!hpage) { count_vm_event(THP_COLLAPSE_ALLOC_FAILED); khugepaged_alloc_sleep(); + try_to_freeze(); } else count_vm_event(THP_COLLAPSE_ALLOC); } while (unlikely(!hpage) && @@ -2331,7 +2332,7 @@ static int khugepaged(void *none) { struct mm_slot *mm_slot; - set_freezable(); + set_freezable_with_signal(); set_user_nice(current, 19); /* serialize with start_khugepaged() */