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=-16.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 CA593C64E8A for ; Wed, 2 Dec 2020 12:21:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 65EE4221FE for ; Wed, 2 Dec 2020 12:21:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729332AbgLBMVJ (ORCPT ); Wed, 2 Dec 2020 07:21:09 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50986 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726817AbgLBMVJ (ORCPT ); Wed, 2 Dec 2020 07:21:09 -0500 Received: from mail-pj1-x1041.google.com (mail-pj1-x1041.google.com [IPv6:2607:f8b0:4864:20::1041]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 16AF1C0613CF for ; Wed, 2 Dec 2020 04:20:23 -0800 (PST) Received: by mail-pj1-x1041.google.com with SMTP id o7so891054pjj.2 for ; Wed, 02 Dec 2020 04:20:23 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=7FKe5u39kZa3azkaY3U9g1f4IsOfUHKX7jY6pnUAmOY=; b=V3xlJkKZ70acNNBym+d6CYtKp1yDDc4ID6bmQ6KHu8jjBR61rLRA/1N/Ch62RjkzT8 SB0iV7jebdkFq/+sFyWs4GSTf3g+I6R4qkhXUXPAdC7UPrV9Jspern7G72Baamtx0fhf 1D2RTFqb9VExlgYlhkSeu1u9U0pMVXt+D17FGVhDmilkOKAMOUeeD+7omPQMztjpd3yS RGAI3GKCD3b/DrvlNiHWNiD4L4scifVM1cm0pe8CswTLjofiaIkPqZn9cTPxqOlgwrvf 1xBLgBsjdwVOZu2S8xqnpULrVGBeJ6EFhJrNJiltJiX9FuH0AQHSTS1/FtsSkPoXgomm mTnA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=7FKe5u39kZa3azkaY3U9g1f4IsOfUHKX7jY6pnUAmOY=; b=qVn7CBIrIzqcyE6MeiON/8NWPWvQxTJiMmWFxN3li4rPecUDTc7FZc1gcM+kRXvtwT JxGL+E9lCyYfBxCZYzRmYLM7s10n+3P/vCxt5y1v1ESjmi0cg3G0KsNufndksVtRfrX9 sCwASf1omp1T2t090G6kldVV/nl9oGELxNGABfrFht8Ufs4NJahsoYnZ+cLDRg7ubgv9 CErFqBKX8MfBBc3VlhyeI7h9KXmrHUX7miRM1iEzP189XrvH8Hl5nn9GVDySDybnuiEY xvn4Y/4v1Q21ABpTids7oVTZth5Qd3K95goHHyxftihQYj5Hu3qO0pRDp0qdqSnU6WqC 0DcQ== X-Gm-Message-State: AOAM531kMlQrwUFcH5ZHj970QA1JgvMpFuy9SJ6buYXUVbALqNA//V2G YQ31oyRG6N0sXC7JeKXrS5nQWg== X-Google-Smtp-Source: ABdhPJysL+XklWYuRtEfA6QYEVT41b0A/ZoAWdmup3o7oQPNXQ9BGs9HvZUlvd5q/8z49Sg10YEijg== X-Received: by 2002:a17:90a:f0c1:: with SMTP id fa1mr1963337pjb.148.1606911622703; Wed, 02 Dec 2020 04:20:22 -0800 (PST) Received: from localhost.localdomain ([103.136.221.70]) by smtp.gmail.com with ESMTPSA id d68sm2320129pfc.135.2020.12.02.04.20.20 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Wed, 02 Dec 2020 04:20:22 -0800 (PST) From: Muchun Song To: akpm@linux-foundation.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Muchun Song Subject: [PATCH] mm/page_alloc: speeding up the iteration of max_order Date: Wed, 2 Dec 2020 20:18:38 +0800 Message-Id: <20201202121838.75218-1-songmuchun@bytedance.com> X-Mailer: git-send-email 2.21.0 (Apple Git-122) MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When we free a page whose order is very close to MAX_ORDER and greater than pageblock_order, it wastes some CPU cycles to increase max_order to MAX_ORDER one by one and check the pageblock migratetype of that page repeatedly especially when MAX_ORDER is much larger than pageblock_order. Signed-off-by: Muchun Song --- mm/page_alloc.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 141f12e5142c..959541234e1d 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1041,7 +1041,7 @@ static inline void __free_one_page(struct page *page, pfn = combined_pfn; order++; } - if (max_order < MAX_ORDER) { + if (max_order < MAX_ORDER && order < MAX_ORDER - 1) { /* If we are here, it means order is >= pageblock_order. * We want to prevent merge between freepages on isolate * pageblock and normal pageblock. Without this, pageblock @@ -1062,6 +1062,8 @@ static inline void __free_one_page(struct page *page, is_migrate_isolate(buddy_mt))) goto done_merging; } + if (unlikely(order != max_order - 1)) + max_order = order + 1; max_order++; goto continue_merging; } -- 2.11.0