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 X-Spam-Level: X-Spam-Status: No, score=-17.0 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E13BDC433DB for ; Thu, 21 Jan 2021 17:56:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 891B123A03 for ; Thu, 21 Jan 2021 17:56:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389308AbhAUR4M (ORCPT ); Thu, 21 Jan 2021 12:56:12 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40774 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389229AbhAURzy (ORCPT ); Thu, 21 Jan 2021 12:55:54 -0500 Received: from mail-pl1-x629.google.com (mail-pl1-x629.google.com [IPv6:2607:f8b0:4864:20::629]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7F682C0613D6; Thu, 21 Jan 2021 09:55:13 -0800 (PST) Received: by mail-pl1-x629.google.com with SMTP id d4so1711542plh.5; Thu, 21 Jan 2021 09:55:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=gPMjM19aJ4pm3ETJElwKqqAg8qqzpXB97r3PbN2RvL8=; b=qDC+o38edBIaLnG8PWToxRhj0mPMeIfGyClNNZGIdiSSXZ2tJZWeGMSjqb6Huno5Je +s9NpaIPVTqyciyZTwKM5kcwYq2dDpuaC0zoITN6bASo1/oCbfUYZKU1WDHQFpR4oTNg Q+2MMzLxdK1Ode8CPyEpokjv+oVgNPg+KGhhdt3i2NU2HG/DmJKDhjdILm/UOXIjpOai er6lOvs1xiyuvzkQUHTmK/7TJ35rFG3Qq4hWmU2S0uFXV8TnSr3Uu+mgP7eff89fbX4D Pa584ZSykXNIjOtQdY8kLxVwg4OVsCPqbdHgBWm//V/4HNQhBVmyo2f3msnkwFwkGnCO 2CGA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id :in-reply-to:references:mime-version:content-transfer-encoding; bh=gPMjM19aJ4pm3ETJElwKqqAg8qqzpXB97r3PbN2RvL8=; b=tTIA/jVHiaWhFtKmkLmeBusMNi3TEo0mf+FoqBugcWub+nwYbCFANmEDPMT3qNc1JM /Qo3rRGVHHbPBk3qZh7Mksh1xAym+WJmDtO0vrP/2txQi8opK2bx7bdOp8jwcMEN88gH W2q8nldW+SwdzH+9UNemNxtIsafTT7LCdu2Vn0NHAuzj3E5e7bs7x+48qj10bDtb3C2K z7O7jwQmotu8ejQqBdvwPyOyk+YOef4dOwYtheIP7T4dYS1NwmxKXehA4beWkXA4sKzN iJmxwDBCXVISSlf/KvEIbjfl3en169+/SBL/q2SJ+5gWi0wrnM3JNDXQFoDNnYoA4cu3 Z6LA== X-Gm-Message-State: AOAM532CDtC9IBzIYiTavQ6sOq2dlND4oq9SHORays1d9ET1GZLId40G mfvqFcfozM4rHDcRu/q06/Y= X-Google-Smtp-Source: ABdhPJwua3dS85PxEqSvzV1XHGSp3rtEG3Evxsrqo12dFSbOhRShx1GThlZKPz/+p0B1yNRZEi2OWw== X-Received: by 2002:a17:902:59c7:b029:de:25e7:2426 with SMTP id d7-20020a17090259c7b02900de25e72426mr424509plj.21.1611251713128; Thu, 21 Jan 2021 09:55:13 -0800 (PST) Received: from bbox-1.mtv.corp.google.com ([2620:15c:211:201:74d0:bb24:e25e:dc4d]) by smtp.gmail.com with ESMTPSA id t2sm6897317pju.19.2021.01.21.09.55.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 21 Jan 2021 09:55:12 -0800 (PST) Sender: Minchan Kim From: Minchan Kim To: Andrew Morton Cc: linux-mm , LKML , hyesoo.yu@samsung.com, david@redhat.com, mhocko@suse.com, surenb@google.com, pullip.cho@samsung.com, joaodias@google.com, hridya@google.com, john.stultz@linaro.org, sumit.semwal@linaro.org, linux-media@vger.kernel.org, devicetree@vger.kernel.org, hch@infradead.org, robh+dt@kernel.org, linaro-mm-sig@lists.linaro.org, Minchan Kim Subject: [PATCH v4 2/4] mm: failfast mode with __GFP_NORETRY in alloc_contig_range Date: Thu, 21 Jan 2021 09:55:00 -0800 Message-Id: <20210121175502.274391-3-minchan@kernel.org> X-Mailer: git-send-email 2.30.0.296.g2bfb1c46d8-goog In-Reply-To: <20210121175502.274391-1-minchan@kernel.org> References: <20210121175502.274391-1-minchan@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Contiguous memory allocation can be stalled due to waiting on page writeback and/or page lock which causes unpredictable delay. It's a unavoidable cost for the requestor to get *big* contiguous memory but it's expensive for *small* contiguous memory(e.g., order-4) because caller could retry the request in different range where would have easy migratable pages without stalling. This patch introduce __GFP_NORETRY as compaction gfp_mask in alloc_contig_range so it will fail fast without blocking when it encounters pages needed waiting. Signed-off-by: Minchan Kim --- mm/page_alloc.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index b031a5ae0bd5..1cdc3ee0b22e 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -8491,12 +8491,16 @@ static int __alloc_contig_migrate_range(struct compact_control *cc, unsigned int nr_reclaimed; unsigned long pfn = start; unsigned int tries = 0; + unsigned int max_tries = 5; int ret = 0; struct migration_target_control mtc = { .nid = zone_to_nid(cc->zone), .gfp_mask = GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL, }; + if (cc->alloc_contig && cc->mode == MIGRATE_ASYNC) + max_tries = 1; + migrate_prep(); while (pfn < end || !list_empty(&cc->migratepages)) { @@ -8513,7 +8517,7 @@ static int __alloc_contig_migrate_range(struct compact_control *cc, break; } tries = 0; - } else if (++tries == 5) { + } else if (++tries == max_tries) { ret = ret < 0 ? ret : -EBUSY; break; } @@ -8564,7 +8568,7 @@ int alloc_contig_range(unsigned long start, unsigned long end, .nr_migratepages = 0, .order = -1, .zone = page_zone(pfn_to_page(start)), - .mode = MIGRATE_SYNC, + .mode = gfp_mask & __GFP_NORETRY ? MIGRATE_ASYNC : MIGRATE_SYNC, .ignore_skip_hint = true, .no_set_skip_hint = true, .gfp_mask = current_gfp_context(gfp_mask), -- 2.30.0.296.g2bfb1c46d8-goog