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=-18.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_IN_DEF_DKIM_WL autolearn=unavailable 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 CD8FBC4338F for ; Mon, 26 Jul 2021 01:47:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AEDED60E78 for ; Mon, 26 Jul 2021 01:47:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231372AbhGZBGy (ORCPT ); Sun, 25 Jul 2021 21:06:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54284 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230152AbhGZBGw (ORCPT ); Sun, 25 Jul 2021 21:06:52 -0400 Received: from mail-pj1-x1029.google.com (mail-pj1-x1029.google.com [IPv6:2607:f8b0:4864:20::1029]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7C435C061757 for ; Sun, 25 Jul 2021 18:47:21 -0700 (PDT) Received: by mail-pj1-x1029.google.com with SMTP id o44-20020a17090a0a2fb0290176ca3e5a2fso4758022pjo.1 for ; Sun, 25 Jul 2021 18:47:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:in-reply-to:message-id:references :mime-version; bh=kRanx6zdiIZx2L0mh1uE63PGEjHt+/w4xPUFYD+g1HM=; b=gm9vFCkoUvqsjiaf6Cdl5mV1rCQhdWIGmC+G4CmwqhfiPEp0pZNimiTD5+gl5jguuv kIMsRazmzPePVpfByYmnY/Q7VjnZoMire6uZ5B6nN8qNZQ3kHw+jJvmTJ+V7EHWfaLVt ZuxEvtH3VHye0OJLxryYJFZAAAOdlre9VFgBnLnTvB3JL7PslMQKFUpaxmLMMZ4m8qQA eqGLSuBS0EB6sPcSsx7uYBxowoFwu9ppsKJt9FMTeiSU/PYQSjMcXgfLd9DLrw/PYhYH ZaWZUwvlLpxl8ql6JHVCk1vqPFvEQYqAMvLV0Enh+WybIxxRtb+McbNgy79PAMYuGyFt +j8Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:in-reply-to:message-id :references:mime-version; bh=kRanx6zdiIZx2L0mh1uE63PGEjHt+/w4xPUFYD+g1HM=; b=suOEdy0pg/B9aQ5VJhvQ4VVsy7vUYpQpMMVxydl2Wu3dEvpNmuof7aF5z5VJQuEE6U 8yaj3/dzHJyZpRiAAMmiceQY15oUjw5OQOY3MH4vga+ZJNTBP4kpxfRriv5TeWho95wq DbY1pcM0d/7VdKTXZpVxEqgU5dgpKZSTW7MAObCbPCZJjRji5HLWXHOUwiomB+XCpA5H 7YwlEPN6QfZ6Ua+sIEAKzbwibhxYIelRLio3uhCQ3oVJez+HGtGABcK7bAs06vmwdKlv q3Ha/S1LaErhvM0sFZr4ykXMr67+eEPlmXeqnFmrBxxPvmipIh3neuo+uYNJvISpOF9h QZ7A== X-Gm-Message-State: AOAM5334CAXOI5oWIF/51EPtpVgoTfWWTisoPv/RvefV3PsVWys6nYgq rS/cWS+Mwyn7ZHvGparg15CPEg== X-Google-Smtp-Source: ABdhPJyR0Sm06D4XnVwRwy8FIAvgJ2gpbOZ4EzNVPCIjcx7HA1DkEhjwKPphKlw9sDUo5TdiQV1ZJA== X-Received: by 2002:a17:902:ea09:b029:12b:1dc0:ac74 with SMTP id s9-20020a170902ea09b029012b1dc0ac74mr12451495plg.82.1627264040423; Sun, 25 Jul 2021 18:47:20 -0700 (PDT) Received: from [2620:15c:17:3:ca7d:5de8:9c9:c7c0] ([2620:15c:17:3:ca7d:5de8:9c9:c7c0]) by smtp.gmail.com with ESMTPSA id k20sm11868208pji.3.2021.07.25.18.47.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 25 Jul 2021 18:47:19 -0700 (PDT) Date: Sun, 25 Jul 2021 18:47:18 -0700 (PDT) From: David Rientjes To: Charan Teja Reddy cc: akpm@linux-foundation.org, vbabka@suse.cz, nigupta@nvidia.com, khalid.aziz@oracle.com, vinmenon@codeaurora.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH resend] mm: compaction: optimize proactive compaction deferrals In-Reply-To: <1626869599-25412-1-git-send-email-charante@codeaurora.org> Message-ID: <83f046a3-5afc-fe6d-40dc-d7aee7b7e398@google.com> References: <1626869599-25412-1-git-send-email-charante@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 21 Jul 2021, Charan Teja Reddy wrote: > Vlastimil Babka figured out that when fragmentation score didn't go down > across the proactive compaction i.e. when no progress is made, next wake > up for proactive compaction is deferred for 1 << > COMPACT_MAX_DEFER_SHIFT, i.e. 64 times, with each wakeup interval of > HPAGE_FRAG_CHECK_INTERVAL_MSEC(=500). In each of this wakeup, it just > decrement 'proactive_defer' counter and goes sleep i.e. it is getting > woken to just decrement a counter. The same deferral time can also > achieved by simply doing the HPAGE_FRAG_CHECK_INTERVAL_MSEC << > COMPACT_MAX_DEFER_SHIFT thus unnecessary wakeup of kcompact thread is > avoided thus also removes the need of 'proactive_defer' thread counter. > > Link: https://lore.kernel.org/linux-fsdevel/88abfdb6-2c13-b5a6-5b46-742d12d1c910@suse.cz/ > Signed-off-by: Charan Teja Reddy With Andrew's comment fixup: Acked-by: David Rientjes Thanks, Charan.