From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BA2DEC4167B for ; Wed, 1 Nov 2023 19:39:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345926AbjKATjM (ORCPT ); Wed, 1 Nov 2023 15:39:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48282 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345932AbjKATjK (ORCPT ); Wed, 1 Nov 2023 15:39:10 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2EC51111 for ; Wed, 1 Nov 2023 12:39:05 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BE1CCC433CD; Wed, 1 Nov 2023 19:39:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1698867544; bh=Rucqa5VCKE0D17dT/3yMoRid8k6y5vZQT44JNGEh600=; h=Date:To:From:Subject:From; b=1MJnUdiUpEPmyyPJlh0f/PuYLdt8liby+P0QtxzbtXeB5B5KeWH0k8cNLZZuOxQsf hx+qgBq0/u8cGFTKfuRhS2fhwsEx+Tzdk7KSQBxyQZ4islx5O5Zwcd/nM/0HXVRmu6 QkPmgia9FyjDBAN/E+ypGrO3iNab4QfeXxYdfJlI= Date: Wed, 01 Nov 2023 12:39:02 -0700 To: mm-commits@vger.kernel.org, yosryahmed@google.com, vitaly.wool@konsulko.com, sjenning@redhat.com, shakeelb@google.com, senozhatsky@chromium.org, roman.gushchin@linux.dev, muchun.song@linux.dev, mhocko@kernel.org, hannes@cmpxchg.org, ddstreet@ieee.org, cerasuolodomenico@gmail.com, nphamcs@gmail.com, akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] zswap-export-compression-failure-stats.patch removed from -mm tree Message-Id: <20231101193904.BE1CCC433CD@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The quilt patch titled Subject: zswap: export compression failure stats has been removed from the -mm tree. Its filename was zswap-export-compression-failure-stats.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Nhat Pham Subject: zswap: export compression failure stats Date: Tue, 24 Oct 2023 16:45:09 -0700 During a zswap store attempt, the compression algorithm could fail (for e.g due to the page containing incompressible random data). This is not tracked in any of existing zswap counters, making it hard to monitor for and investigate. We have run into this problem several times in our internal investigations on zswap store failures. This patch adds a dedicated debugfs counter for compression algorithm failures. Link: https://lkml.kernel.org/r/20231024234509.2680539-1-nphamcs@gmail.com Signed-off-by: Nhat Pham Reviewed-by: Sergey Senozhatsky Cc: Dan Streetman Cc: Domenico Cerasuolo Cc: Johannes Weiner Cc: Michal Hocko Cc: Muchun Song Cc: Roman Gushchin Cc: Seth Jennings Cc: Shakeel Butt Cc: Vitaly Wool Cc: Yosry Ahmed Signed-off-by: Andrew Morton --- mm/zswap.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) --- a/mm/zswap.c~zswap-export-compression-failure-stats +++ a/mm/zswap.c @@ -62,6 +62,8 @@ static u64 zswap_pool_limit_hit; static u64 zswap_written_back_pages; /* Store failed due to a reclaim failure after pool limit was reached */ static u64 zswap_reject_reclaim_fail; +/* Store failed due to compression algorithm failure */ +static u64 zswap_reject_compress_fail; /* Compressed page was too big for the allocator to (optimally) store */ static u64 zswap_reject_compress_poor; /* Store failed because underlying allocator could not get memory */ @@ -1312,8 +1314,10 @@ bool zswap_store(struct folio *folio) ret = crypto_wait_req(crypto_acomp_compress(acomp_ctx->req), &acomp_ctx->wait); dlen = acomp_ctx->req->dlen; - if (ret) + if (ret) { + zswap_reject_compress_fail++; goto put_dstmem; + } /* store */ zpool = zswap_find_zpool(entry); @@ -1553,6 +1557,8 @@ static int zswap_debugfs_init(void) zswap_debugfs_root, &zswap_reject_alloc_fail); debugfs_create_u64("reject_kmemcache_fail", 0444, zswap_debugfs_root, &zswap_reject_kmemcache_fail); + debugfs_create_u64("reject_compress_fail", 0444, + zswap_debugfs_root, &zswap_reject_compress_fail); debugfs_create_u64("reject_compress_poor", 0444, zswap_debugfs_root, &zswap_reject_compress_poor); debugfs_create_u64("written_back_pages", 0444, _ Patches currently in -mm which might be from nphamcs@gmail.com are