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=-8.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL autolearn=no 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 BE996C2D0C2 for ; Thu, 2 Jan 2020 19:29:44 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 63D5121D7D for ; Thu, 2 Jan 2020 19:29:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="kqXZVFWT" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 63D5121D7D Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id CAE1C8E0005; Thu, 2 Jan 2020 14:29:43 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id C5DE48E0003; Thu, 2 Jan 2020 14:29:43 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B74728E0005; Thu, 2 Jan 2020 14:29:43 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0179.hostedemail.com [216.40.44.179]) by kanga.kvack.org (Postfix) with ESMTP id A2AA68E0003 for ; Thu, 2 Jan 2020 14:29:43 -0500 (EST) Received: from smtpin06.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with SMTP id 574964995E8 for ; Thu, 2 Jan 2020 19:29:43 +0000 (UTC) X-FDA: 76333683846.06.arm49_37b81daef0a0b X-HE-Tag: arm49_37b81daef0a0b X-Filterd-Recvd-Size: 3785 Received: from mail-il1-f194.google.com (mail-il1-f194.google.com [209.85.166.194]) by imf03.hostedemail.com (Postfix) with ESMTP for ; Thu, 2 Jan 2020 19:29:42 +0000 (UTC) Received: by mail-il1-f194.google.com with SMTP id t17so34834379ilm.13 for ; Thu, 02 Jan 2020 11:29:42 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=+f4I6dJd56gNuARF1DhumTdW9g7oK8nJxnvuK5mh/lk=; b=kqXZVFWTHWFekPnrYtSkyCloqFKcQ1S28Az2zwBzYGVrLUGlgLotV7jiwCmIeWrD/0 sVDACoA8ODcUQkahVIyFxU/y1zHi3g7qASmlcqWb1XgqbqjmWB9RNvNSjPM6gMcG3ZUd bGxSEx9aNJGXb4HyNVAQRwrfwrDT7X1RQMyr/MLdTT4yDrd77nhQM+NZDaWPEmRMy9mu 3Saekevha02GILue1VHO2ondzC/U2M5qDpqNehR7lGYas/zfFTsCC3oWVm5BWvmquE3F nC/q466GioCeb0MsjiuSloZnY7t2SbfyvO+1MEK0moLED5/3ijbH7UljRM2RLzgoouri qRPQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=+f4I6dJd56gNuARF1DhumTdW9g7oK8nJxnvuK5mh/lk=; b=CIcsmuZwa5udn8W+v81p3h8hOadY6JkdOEdQf+xk/kZxEg0NETFAW9XIs6lFG5DmHQ WnsFoouHMWaTXvKPY3PmbzWzbbBNmCdWLj7mhcyYAugpMzNHPUByApmffneWg0D4KXvA 4v9oRltgrIm8JvBL5rDUBB0Yemb4w4NusRptYo/z11ABhx2/mGyK2aQQxe0VUNPw3gmw u7I9MXMhKsbuCOl2lCYc0V8MbM+/tJ38WbUS8QcjW3HwUOAFI2MUJpiEpeBamNccuwy/ 5XPLgiGd9quyE2wEcIggrSoxmUhE5gkbu45h4OsCoOdygZ/eNqb9HzMybgieOjw3Uok0 Hhiw== X-Gm-Message-State: APjAAAVQhHsDIdC3M8bDRJdlq3l8orkpy7PGiLkKRfd76mHhAwYJMXeL khwnmUSZnt2ClaGkGHPCr/+Z5fdal+rlnR/USKmvOA== X-Google-Smtp-Source: APXvYqybA/zGY4jsM+xVuQPCwje+uyffjZRtCp8dHzF3W4LR3wjMsiUpgFdAtaqYIvAg0htdbykSfJNwE6QV1qtOxKQ= X-Received: by 2002:a92:8dda:: with SMTP id w87mr70909697ill.55.1577993381778; Thu, 02 Jan 2020 11:29:41 -0800 (PST) MIME-Version: 1.0 References: <20191227213439.139123-1-semenzato@google.com> <20191227213439.139123-2-semenzato@google.com> <20191228002503.GB544630@chrisdown.name> In-Reply-To: <20191228002503.GB544630@chrisdown.name> From: Luigi Semenzato Date: Thu, 2 Jan 2020 11:29:30 -0800 Message-ID: Subject: Re: [PATCH 1/2] Documentation: clarify limitations of hibernation To: Chris Down Cc: Linux Memory Management List Content-Type: text/plain; charset="UTF-8" X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Thank you Chris, those are excellent comments. I am replacing "memory pressure" with "memory usage". I had used "pressure" because "usage" is vague and here we specifically refer to non-reclaimable pages. But it's true that "pressure" has a different, specific meaning for the mm, so "usage" is better. The example should clarify the problem. I am also removing the workaround. I thought it may be useful, but as you said, it's quite debatable that it belongs here. On Fri, Dec 27, 2019 at 4:25 PM Chris Down wrote: > > Oh, and: > > Luigi Semenzato writes: > >+system to be present for the underlying CPU architecture. Additionally, the > >+current implementation can enter the hibernation state only when memory > >+pressure is low (see "Limitations" below). > > This doesn't seem to make much sense to me. You claim it only works when > pressure is low, but then suggest people raise pressure to fix it. > > I suppose you mean "only when memory *usage* is low"? I mean, if memory > pressure is low, then it's likely to result in these cold pages sitting around > in the first place.