From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753353AbZGXQNu (ORCPT ); Fri, 24 Jul 2009 12:13:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753331AbZGXQNs (ORCPT ); Fri, 24 Jul 2009 12:13:48 -0400 Received: from cam-admin0.cambridge.arm.com ([193.131.176.58]:51168 "EHLO cam-admin0.cambridge.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752410AbZGXQMO (ORCPT ); Fri, 24 Jul 2009 12:12:14 -0400 Subject: [PATCH 2/8] kmemleak: Allow rescheduling during an object scanning To: linux-kernel@vger.kernel.org From: Catalin Marinas Date: Fri, 24 Jul 2009 17:12:13 +0100 Message-ID: <20090724161213.5752.41867.stgit@pc1117.cambridge.arm.com> In-Reply-To: <20090724161026.5752.52503.stgit@pc1117.cambridge.arm.com> References: <20090724161026.5752.52503.stgit@pc1117.cambridge.arm.com> User-Agent: StGit/0.15-rc1-9-gd8846 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 24 Jul 2009 16:12:13.0455 (UTC) FILETIME=[815F19F0:01CA0C79] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If the object size is bigger than a predefined value (4K in this case), release the object lock during scanning and call cond_resched(). Re-acquire the lock after rescheduling and test whether the object is still valid. Signed-off-by: Catalin Marinas --- mm/kmemleak.c | 19 +++++++++++++++---- 1 files changed, 15 insertions(+), 4 deletions(-) diff --git a/mm/kmemleak.c b/mm/kmemleak.c index 7e8e4b0..c665626 100644 --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -107,6 +107,7 @@ #define SECS_FIRST_SCAN 60 /* delay before the first scan */ #define SECS_SCAN_WAIT 600 /* subsequent auto scanning delay */ #define GRAY_LIST_PASSES 25 /* maximum number of gray list scans */ +#define MAX_SCAN_SIZE 4096 /* maximum size of a scanned block */ #define BYTES_PER_POINTER sizeof(void *) @@ -950,10 +951,20 @@ static void scan_object(struct kmemleak_object *object) if (!(object->flags & OBJECT_ALLOCATED)) /* already freed object */ goto out; - if (hlist_empty(&object->area_list)) - scan_block((void *)object->pointer, - (void *)(object->pointer + object->size), object, 0); - else + if (hlist_empty(&object->area_list)) { + void *start = (void *)object->pointer; + void *end = (void *)(object->pointer + object->size); + + while (start < end && (object->flags & OBJECT_ALLOCATED)) { + scan_block(start, min(start + MAX_SCAN_SIZE, end), + object, 0); + start += MAX_SCAN_SIZE; + + spin_unlock_irqrestore(&object->lock, flags); + cond_resched(); + spin_lock_irqsave(&object->lock, flags); + } + } else hlist_for_each_entry(area, elem, &object->area_list, node) scan_block((void *)(object->pointer + area->offset), (void *)(object->pointer + area->offset