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 72A7CC433FE for ; Tue, 15 Nov 2022 09:20:35 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ous6g-0007ah-QK; Tue, 15 Nov 2022 04:19:50 -0500 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 1ous6e-0007Wc-7B for qemu-devel@nongnu.org; Tue, 15 Nov 2022 04:19:48 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ous6c-0004ob-9Q for qemu-devel@nongnu.org; Tue, 15 Nov 2022 04:19:47 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1668503985; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:in-reply-to:in-reply-to: references:references; bh=nPAmylOoEwlBBRK7L/VHpaIWyynNrrSlD4Sx6EILJ8c=; b=S43hElKU/qlApmoPbOUoH1ODL5IImc9tJsI1AOBXmr9lCkFpMicboAXMb04W3Ya1o0pQXs /kpgxCJVhBBgV25azblvVxtLlV91OCu7qbyrAUuapqboovXypA6nKid8Q97hXyZYzdymSM FUNG+/GC/R7efqbvGXZ5i8ssZj1JckU= Received: from mail-wr1-f71.google.com (mail-wr1-f71.google.com [209.85.221.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_128_GCM_SHA256) id us-mta-639-768_9fIEPNeKHnkGT-8BfA-1; Tue, 15 Nov 2022 04:19:43 -0500 X-MC-Unique: 768_9fIEPNeKHnkGT-8BfA-1 Received: by mail-wr1-f71.google.com with SMTP id c18-20020adfa312000000b002364fabf2ceso2563124wrb.2 for ; Tue, 15 Nov 2022 01:19:43 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=mime-version:message-id:date:reply-to:user-agent:references :in-reply-to:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=nPAmylOoEwlBBRK7L/VHpaIWyynNrrSlD4Sx6EILJ8c=; b=Qcgyb6/3cEv0Vpe8vpSAGP/Pp0T/c7/9mPcIYDG63/s7xPoeJgJUVdC/VXh7zBG2mU MZaNsavF9Fgc3+yPQMkdqFxbX3ClJl2Jj9gpw8/4G9+avuimRLd7XnDyvsCAfJvNCeKT 4RZ/z8lB2p/0OLLBv36bxWnoFMeLcGoGkLPkql/N9lGGZxK+P9adTiU4asH582OHP1Ac RsoyFt0/Ro1LRuqUGEbfjgtn7hJYTvJRRNt3SVaKofC2nu3Rj4Da5t5kQH7+HqRcxfmL jFM2xusEXSF8ffuTrrJlO+N+MjPmKnBSQucVIMjqh9PdY5ttrjxmK2S1Lou226G+U4uw doNg== X-Gm-Message-State: ANoB5pk76pMlb476ocOVytUtsjoimF8jkr/pvhDbkrHYTT3r0cTSnbDy WS/hE9Th9qgff+f75UqSgETA2IevOFy+ukVXYcavR4yCpUDM+djbplRIIBVh47lPPeXNLSU6d8n j7AeJCmfl/71wf/g= X-Received: by 2002:a5d:528c:0:b0:22f:da60:345 with SMTP id c12-20020a5d528c000000b0022fda600345mr9936884wrv.218.1668503982382; Tue, 15 Nov 2022 01:19:42 -0800 (PST) X-Google-Smtp-Source: AA0mqf7dByMplU4mRwMsWi/CN744Q6UVV9zdpYUw5qNjqnvmUtG/RYg8BGo7ysMoALU7+zLM097MeA== X-Received: by 2002:a5d:528c:0:b0:22f:da60:345 with SMTP id c12-20020a5d528c000000b0022fda600345mr9936868wrv.218.1668503982143; Tue, 15 Nov 2022 01:19:42 -0800 (PST) Received: from localhost ([31.4.176.165]) by smtp.gmail.com with ESMTPSA id g16-20020a7bc4d0000000b003cf75f56105sm17054070wmk.41.2022.11.15.01.19.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 15 Nov 2022 01:19:41 -0800 (PST) From: Juan Quintela To: Peter Xu Cc: "Dr. David Alan Gilbert" , qemu-devel@nongnu.org, "Daniel P . Berrange" , ani@anisinha.ca, Leonardo Bras Soares Passos , Manish Mishra Subject: Re: [PATCH v2 06/15] migration: Yield bitmap_mutex properly when sending/sleeping In-Reply-To: (Peter Xu's message of "Thu, 13 Oct 2022 12:19:23 -0400") References: <20221011215559.602584-1-peterx@redhat.com> <20221011215559.602584-7-peterx@redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.1 (gnu/linux) Date: Tue, 15 Nov 2022 10:19:40 +0100 Message-ID: <8735akh8wj.fsf@secure.mitica> MIME-Version: 1.0 Content-Type: text/plain Received-SPF: pass client-ip=170.10.129.124; envelope-from=quintela@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 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: , Reply-To: quintela@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Peter Xu wrote: > On Wed, Oct 12, 2022 at 01:51:07PM -0400, Peter Xu wrote: >> On Wed, Oct 12, 2022 at 05:43:53PM +0100, Dr. David Alan Gilbert wrote: >> > * Peter Xu (peterx@redhat.com) wrote: >> > > Don't take the bitmap mutex when sending pages, or when being throttled by >> > > migration_rate_limit() (which is a bit tricky to call it here in ram code, >> > > but seems still helpful). >> > > >> > > It prepares for the possibility of concurrently sending pages in >1 threads >> > > using the function ram_save_host_page() because all threads may need the >> > > bitmap_mutex to operate on bitmaps, so that either sendmsg() or any kind of >> > > qemu_sem_wait() blocking for one thread will not block the other from >> > > progressing. >> > > >> > > Signed-off-by: Peter Xu >> > >> > Reviewed-by: Dr. David Alan Gilbert >> > >> > although a comment above the reclaration of ram_save_host_pages saying >> > it can drop the lock would be veyr good. >> >> Let me add that. Thanks, > > A fixup to this patch attached to touch up the comment for > ram_save_host_page(). Reviewed-by: Juan Quintela