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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 37EA1C77B61 for ; Thu, 27 Apr 2023 10:10:29 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pryZe-0003Wi-B4; Thu, 27 Apr 2023 06:10:02 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pryZa-0003UD-3Q for qemu-devel@nongnu.org; Thu, 27 Apr 2023 06:10:00 -0400 Received: from mail-ed1-x52b.google.com ([2a00:1450:4864:20::52b]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1pryZU-0002mh-W0 for qemu-devel@nongnu.org; Thu, 27 Apr 2023 06:09:54 -0400 Received: by mail-ed1-x52b.google.com with SMTP id 4fb4d7f45d1cf-505035e3368so14349104a12.0 for ; Thu, 27 Apr 2023 03:09:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1682590191; x=1685182191; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=mqFQr8e6pBaDzauVe8ZGgXZVMUHo7kGeUeG+Seb+BxE=; b=gWFmL0qE9SSZQOKoWdtb5faHUCg2WNrnqzJYtNyOskjnabFkYzrNj7DSBdFfmS046o dmF48DfhJEOhKP2/Ec5xKXzPOPttcF3+G9k4q6rKTlftveCnsOFWJIh9dsEMOccGkCVB Dv6WKkoevlLUoR/SQd9dWrF8MBYFk1wSYwgRd4dRXJn1uZT0IEL59rtlvSPyj2A1OEpt XSjJCNB7TX5S+xBwjkvQc99jvAwerJJ1K6vh+yRkxZ48Xdz9nPqJqwC17c0WWdgeVti2 e8st9y7m6nMUA0xqB/CYH/NElN/5c74WOKHwdRB/70QAZLpQOpnFDdai2L7+UbZqUGPe nqaA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1682590191; x=1685182191; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=mqFQr8e6pBaDzauVe8ZGgXZVMUHo7kGeUeG+Seb+BxE=; b=GyzTiD7HgCyWLCG9VExw5UCWfJ97TtLS0a020xIaMmQJx2TckEgXx3m/SU0HTa5g5s lFGAyGhIiWSpMjQn72sqq4KtX1Ap/CeSqur7O6ciPXBu7aWPbEC3fIHr/ryDqYSDr76d 45FHLjRj4LoPGYLoEU3ZsIyRvw1XAguCDS90C1z2GIgrO8iisLps/rTKR7yKumA9K52f fpel4WCr2d0ukGlaqhtuGLBdzjXqawKnX8F7kItT2FP/3unqSSMvONwAPIHBlc98MkAb 2izNmQPXYgjikPv+42whdEu43kHX2OLQyCxLePLmYd0pk1PflOyUTjmfDENReMWKw58c Mxrw== X-Gm-Message-State: AC+VfDxTxcCEU4ag2sV+TLLqsAX/Vr+mH+Mbv5RQ252aXmuE5lSl5zk2 r2irj263mwoC5obcQwTVT6i0ag== X-Google-Smtp-Source: ACHHUZ6FT2Nu92v8rMwtV60YKlTbw6JAxAa00ZxDuG+aouGoU/8hNeHgyQWLRJINJOn4Q/zVhhSVQA== X-Received: by 2002:aa7:cc97:0:b0:506:75d4:44 with SMTP id p23-20020aa7cc97000000b0050675d40044mr1039833edt.25.1682590191373; Thu, 27 Apr 2023 03:09:51 -0700 (PDT) Received: from [172.23.3.19] ([195.167.132.10]) by smtp.gmail.com with ESMTPSA id bq6-20020a056402214600b0050470aa444fsm7721629edb.51.2023.04.27.03.09.50 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 27 Apr 2023 03:09:51 -0700 (PDT) Message-ID: Date: Thu, 27 Apr 2023 11:09:50 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.10.0 Subject: Re: [PATCH v6 3/3] migration: Make dirty_bytes_last_sync atomic Content-Language: en-US To: Juan Quintela , qemu-devel@nongnu.org Cc: Peter Xu , Leonardo Bras , Paolo Bonzini References: <20230427095250.22350-1-quintela@redhat.com> <20230427095250.22350-4-quintela@redhat.com> From: Richard Henderson In-Reply-To: <20230427095250.22350-4-quintela@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=2a00:1450:4864:20::52b; envelope-from=richard.henderson@linaro.org; helo=mail-ed1-x52b.google.com X-Spam_score_int: -34 X-Spam_score: -3.5 X-Spam_bar: --- X-Spam_report: (-3.5 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, NICE_REPLY_A=-1.422, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On 4/27/23 10:52, Juan Quintela wrote: > As we set its value, it needs to be operated with atomics. > We rename it from remaining to better reflect its meaning. > > Statistics always return the real reamaining bytes. This was used to > store how much pages where dirty on the previous generation, so we can > calculate the expected downtime as: dirty_bytes_last_sync / > current_bandwith. > > If we use the actual remaining bytes, we would see a very small value > at the end of the iteration. > > Signed-off-by: Juan Quintela > Reviewed-by: Peter Xu > > --- > > I am open to use ram_bytes_remaining() in its only use and be more > "optimistic" about the downtime. > > Don't use __nocheck() functions. > Use stat64_get() now that it exists. > --- > migration/migration.c | 3 ++- > migration/ram.c | 2 +- > migration/ram.h | 2 +- > 3 files changed, 4 insertions(+), 3 deletions(-) Reviewed-by: Richard Henderson r~