From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751605AbaAMLVd (ORCPT ); Mon, 13 Jan 2014 06:21:33 -0500 Received: from mail-pa0-f42.google.com ([209.85.220.42]:36911 "EHLO mail-pa0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751729AbaAMLTX (ORCPT ); Mon, 13 Jan 2014 06:19:23 -0500 From: Minchan Kim To: Andrew Morton Cc: linux-kernel@vger.kernel.org, Nitin Gupta , Jerome Marchand , Sergey Senozhatsky , Minchan Kim Subject: [PATCH 2/7] zram: delay pending free request in read path Date: Mon, 13 Jan 2014 20:18:57 +0900 Message-Id: <1389611942-15544-3-git-send-email-minchan@kernel.org> X-Mailer: git-send-email 1.8.4.3 In-Reply-To: <1389611942-15544-1-git-send-email-minchan@kernel.org> References: <1389611942-15544-1-git-send-email-minchan@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Sergey Senozhatsky reporetd we don't need to handle pending free request every I/O so that this patch removes it in read path while we remain it in write path. Let's consider below example. Swap subsystem ask to zram "A" block free by swap_slot_free_notify but zram had been pended it without real freeing. Swap subsystem allocates "A" block for new data but request pended for a long time just handled and zram blindly free new data on the "A" block. :( That's why we couldn't remove handle pending free request right before zram-write. Signed-off-by: Minchan Kim --- drivers/block/zram/zram_drv.c | 1 - 1 file changed, 1 deletion(-) diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 213dfc1..d87c7e9 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -535,7 +535,6 @@ static int zram_bvec_rw(struct zram *zram, struct bio_vec *bvec, u32 index, 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 { -- 1.8.4.3