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 7FC88C7EE2D for ; Thu, 1 Jun 2023 19:36:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231513AbjFATgg (ORCPT ); Thu, 1 Jun 2023 15:36:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34682 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231246AbjFATge (ORCPT ); Thu, 1 Jun 2023 15:36:34 -0400 Received: from mail-qt1-x82e.google.com (mail-qt1-x82e.google.com [IPv6:2607:f8b0:4864:20::82e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 55D7D186 for ; Thu, 1 Jun 2023 12:36:32 -0700 (PDT) Received: by mail-qt1-x82e.google.com with SMTP id d75a77b69052e-3f80e055549so9512781cf.3 for ; Thu, 01 Jun 2023 12:36:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cmpxchg-org.20221208.gappssmtp.com; s=20221208; t=1685648191; x=1688240191; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=YMBOA4WH9GmX8va2TeN6IF1hKckQ4hk2vM+qJu7Yuk8=; b=JKQScWQlepZwk1rwr8D4B8rhFPkzPfrRjo7oBWfw+nEP9EfqxAcT+QW4osjwPhmT5Q ZQV6JWXs8rJRB3wOSil33aA6VH95iOYN6NoX5pyxPzvm5t4sMk6BhLLDlzYUm0BDj51b NzeK/c8Vw1d6f0CTxvogTrH8Jj3bZjQMBYb3ccX2/bMjCwpvFGw6aikcmLyNiBcs4KEU czOUcxsiQkOFgG8W7JYe0fmkQADh9wc7yDtbyUxt+Mn4vHqjpz7R6q6mj9tnNkmcZpcb 6qOD1px5L7EOtewVnd2LWHez4iP7SCtbcRjjzfJCt5Ov8Ju3NzRD7iK3yEysqmi3RAWk z6WA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1685648191; x=1688240191; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=YMBOA4WH9GmX8va2TeN6IF1hKckQ4hk2vM+qJu7Yuk8=; b=NbnQDMQix7dbhvzilEq0K5yjtUDKUr/YnYrSC1LY4PpXOsmr3rjBX6Hr8wxGZKZBHa v/5PIrNk8vogvL/RZv/BSa/yr+VmfkdFgHANB9joV84qAhZTaZbTTvuYbIm/m0em5dd3 hlSF+SFQEjOkSAzZWq+RZhQ344Yg7TpAeQvZnvW/xQ2dq8mom7Rfk4T4Z5rV3UI0cuXh 6acLKdKEnAKeyLT7QVFN6+ZdfbbW2S6z/SiHyx/HDsIvBntIMOv0+Ove/S3NjUE2usBp 0MQHypzbKhRACsrR3JqLWEVPspNCUByceUlO5T65Q8nArznYfXYYhmmXDGpGVEIU6Qyk Gxog== X-Gm-Message-State: AC+VfDzIaczX0TQdV1eRDyp5b4sKQ8mkWrAyNmCMr+fTw+8MmUoGivOC Fy1hv07YMGhRo6cqW11+L05KHg== X-Google-Smtp-Source: ACHHUZ7CZ13+q3p59s8LZm39fYm6itDCPooJs/hGoBcJsKdzQMerh2esQX0ar5jZ58mA8fqbfZLxrQ== X-Received: by 2002:a05:622a:4d:b0:3f7:fcb1:3153 with SMTP id y13-20020a05622a004d00b003f7fcb13153mr11551235qtw.30.1685648191239; Thu, 01 Jun 2023 12:36:31 -0700 (PDT) Received: from localhost ([2620:10d:c091:400::5:ec58]) by smtp.gmail.com with ESMTPSA id g11-20020ac8774b000000b003eda962ed24sm7973574qtu.22.2023.06.01.12.36.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 01 Jun 2023 12:36:30 -0700 (PDT) Date: Thu, 1 Jun 2023 15:36:30 -0400 From: Johannes Weiner To: Dan Schatzberg Cc: Tejun Heo , Chris Down , Zefan Li , Jonathan Corbet , "open list:CONTROL GROUP (CGROUP)" , "open list:DOCUMENTATION" , open list Subject: Re: [PATCH] Documentation: Clarify usage of memory limits Message-ID: <20230601193630.GA157732@cmpxchg.org> References: <20230601183820.3839891-1-schatzberg.dan@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230601183820.3839891-1-schatzberg.dan@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 01, 2023 at 11:38:19AM -0700, Dan Schatzberg wrote: > The existing documentation refers to memory.high as the "main mechanism > to control memory usage." This seems incorrect to me - memory.high can > result in reclaim pressure which simply leads to stalls unless some > external component observes and actions on it (e.g. systemd-oomd can be > used for this purpose). While this is feasible, users are unaware of > this interaction and are led to believe that memory.high alone is an > effective mechanism for limiting memory. > > The documentation should recommend the use of memory.max as the > effective way to enforce memory limits - it triggers reclaim and results > in OOM kills by itself. > > Signed-off-by: Dan Schatzberg Yeah, this is quite stale. How this ended up working in practice is a bit different from how we initially conceived it. Thanks for updating it. Acked-by: Johannes Weiner