From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752742AbbGKGhU (ORCPT ); Sat, 11 Jul 2015 02:37:20 -0400 Received: from mail-pd0-f169.google.com ([209.85.192.169]:35479 "EHLO mail-pd0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751809AbbGKGhS (ORCPT ); Sat, 11 Jul 2015 02:37:18 -0400 From: Sergey Senozhatsky To: Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Sergey Senozhatsky , Sergey Senozhatsky Subject: [PATCH 2/2] mm/shrinker: add init_shrinker() function Date: Sat, 11 Jul 2015 11:51:55 +0900 Message-Id: <1436583115-6323-3-git-send-email-sergey.senozhatsky@gmail.com> X-Mailer: git-send-email 2.4.5 In-Reply-To: <1436583115-6323-1-git-send-email-sergey.senozhatsky@gmail.com> References: <1436583115-6323-1-git-send-email-sergey.senozhatsky@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org All zeroes shrinker is now treated as 'initialized, but not registered'. If, for some reason, you can't zero your shrinker struct (or don't want to) then use init_shrinker() function. Otherwise, in some cases, unregister_shrinker() may Oops. Signed-off-by: Sergey Senozhatsky --- include/linux/shrinker.h | 1 + mm/vmscan.c | 12 ++++++++++++ 2 files changed, 13 insertions(+) diff --git a/include/linux/shrinker.h b/include/linux/shrinker.h index 4fcacd9..bffb660 100644 --- a/include/linux/shrinker.h +++ b/include/linux/shrinker.h @@ -67,6 +67,7 @@ struct shrinker { #define SHRINKER_NUMA_AWARE (1 << 0) #define SHRINKER_MEMCG_AWARE (1 << 1) +extern void init_shrinker(struct shrinker *); extern int register_shrinker(struct shrinker *); extern void unregister_shrinker(struct shrinker *); #endif diff --git a/mm/vmscan.c b/mm/vmscan.c index cadc8a2..4bbcfcf 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -221,6 +221,18 @@ static unsigned long get_lru_size(struct lruvec *lruvec, enum lru_list lru) } /* + * All-zeroes shrinker considered to be initialized. Use this + * function if you can't (don't want to) zero out your shrinker + * structure. + */ +void init_shrinker(struct shrinker *shrinker) +{ + shrinker->nr_deferred = NULL; + INIT_LIST_HEAD(&shrinker->list); +} +EXPORT_SYMBOL(init_shrinker); + +/* * Add a shrinker callback to be called from the vm. */ int register_shrinker(struct shrinker *shrinker) -- 2.4.5