Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751469Ab3IFNsa (ORCPT ); Fri, 6 Sep 2013 09:48:30 -0400 Received: from mail-pb0-f52.google.com ([209.85.160.52]:45779 "EHLO mail-pb0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751281Ab3IFNs3 (ORCPT ); Fri, 6 Sep 2013 09:48:29 -0400 Date: Fri, 6 Sep 2013 16:47:06 +0300 From: Sergey Senozhatsky To: Greg Kroah-Hartman Cc: Minchan Kim , devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org Subject: [PATCH 1/2] staging: zram: minimize `slot_free_lock' usage Message-ID: <20130906134706.GA2238@swordfish.minsk.epam.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1339 Lines: 40 Calling handle_pending_slot_free() for every RW operation may cause unneccessary slot_free_lock locking, because most likely process will see NULL slot_free_rq. handle_pending_slot_free() only when current detects that slot_free_rq is not NULL. Signed-off-by: Sergey Senozhatsky --- drivers/staging/zram/zram_drv.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/staging/zram/zram_drv.c b/drivers/staging/zram/zram_drv.c index 91d94b5..17386e2 100644 --- a/drivers/staging/zram/zram_drv.c +++ b/drivers/staging/zram/zram_drv.c @@ -532,14 +532,15 @@ static int zram_bvec_rw(struct zram *zram, struct bio_vec *bvec, u32 index, { int ret; + if (zram->slot_free_rq) + handle_pending_slot_free(zram); + if (rw == READ) { down_read(&zram->lock); - handle_pending_slot_free(zram); ret = zram_bvec_read(zram, bvec, index, offset, bio); up_read(&zram->lock); } else { down_write(&zram->lock); - handle_pending_slot_free(zram); ret = zram_bvec_write(zram, bvec, index, offset); up_write(&zram->lock); } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/