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=-15.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 D3A7EC433C1 for ; Thu, 25 Mar 2021 18:17:54 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 3F73061A2B for ; Thu, 25 Mar 2021 18:17:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3F73061A2B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:38220 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lPUYK-0001xX-12 for qemu-devel@archiver.kernel.org; Thu, 25 Mar 2021 14:17:52 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:36576) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lPUPf-0006XP-HQ for qemu-devel@nongnu.org; Thu, 25 Mar 2021 14:08:57 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:54524) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lPUPW-0005SR-Hz for qemu-devel@nongnu.org; Thu, 25 Mar 2021 14:08:54 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1616695724; h=from:from: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=iW6MPiiLc2VeEXd6tDVO4b4SiIk/uzIGtu10p3pVSMQ=; b=HAaZfxd2TP8lJxL4bE/3wGDfciYbzNKQXNCpDYshnH/e/f9Dbr+vfXYE4iTvrEOKfda69e JZERCXXj6+YXWoGb5YYfw4WJf4zmgznHpo9hXmXBo/sT/dRxAKIJ1Ou+fImXOuys11vc4d KUjwrzaoCFpYYqXmCJlXtAQdlpsLUTQ= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-50-VXhnSyvfNKOWYcN2gfpLQg-1; Thu, 25 Mar 2021 14:08:42 -0400 X-MC-Unique: VXhnSyvfNKOWYcN2gfpLQg-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 76E1E180FCAD; Thu, 25 Mar 2021 18:07:47 +0000 (UTC) Received: from work-vm (ovpn-112-89.ams2.redhat.com [10.36.112.89]) by smtp.corp.redhat.com (Postfix) with ESMTPS id C0E6719C59; Thu, 25 Mar 2021 18:07:45 +0000 (UTC) Date: Thu, 25 Mar 2021 18:07:42 +0000 From: "Dr. David Alan Gilbert" To: leirao Subject: Re: [PATCH v4 09/10] Add the function of colo_bitmap_clear_diry. Message-ID: References: <1616639091-28279-1-git-send-email-lei.rao@intel.com> <1616639091-28279-10-git-send-email-lei.rao@intel.com> MIME-Version: 1.0 In-Reply-To: <1616639091-28279-10-git-send-email-lei.rao@intel.com> User-Agent: Mutt/2.0.6 (2021-03-06) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dgilbert@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Received-SPF: pass client-ip=170.10.133.124; envelope-from=dgilbert@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_H4=0.001, RCVD_IN_MSPIKE_WL=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: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: lukasstraub2@web.de, lizhijian@cn.fujitsu.com, quintela@redhat.com, jasowang@redhat.com, qemu-devel@nongnu.org, chen.zhang@intel.com, pbonzini@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" * leirao (lei.rao@intel.com) wrote: > From: "Rao, Lei" > > When we use continuous dirty memory copy for flushing ram cache on > secondary VM, we can also clean up the bitmap of contiguous dirty > page memory. This also can reduce the VM stop time during checkpoint. > > Signed-off-by: Lei Rao > --- > migration/ram.c | 29 +++++++++++++++++++++++++---- > 1 file changed, 25 insertions(+), 4 deletions(-) > > diff --git a/migration/ram.c b/migration/ram.c > index a258466..ae1e659 100644 > --- a/migration/ram.c > +++ b/migration/ram.c > @@ -855,6 +855,30 @@ unsigned long colo_bitmap_find_dirty(RAMState *rs, RAMBlock *rb, > return first; > } > > +/** > + * colo_bitmap_clear_dirty:when we flush ram cache to ram, we will use > + * continuous memory copy, so we can also clean up the bitmap of contiguous > + * dirty memory. > + */ > +static inline bool colo_bitmap_clear_dirty(RAMState *rs, > + RAMBlock *rb, > + unsigned long start, > + unsigned long num) > +{ > + bool ret; > + unsigned long i = 0; > + > + qemu_mutex_lock(&rs->bitmap_mutex); Please use QEMU_LOCK_GUARD(&rs->bitmap_mutex); > + for (i = 0; i < num; i++) { > + ret = test_and_clear_bit(start + i, rb->bmap); > + if (ret) { > + rs->migration_dirty_pages--; > + } > + } > + qemu_mutex_unlock(&rs->bitmap_mutex); > + return ret; This implementation is missing the clear_bmap code that migration_bitmap_clear_dirty has. I think that's necessary now. Are we sure there's any benefit in this? Dave > +} > + > static inline bool migration_bitmap_clear_dirty(RAMState *rs, > RAMBlock *rb, > unsigned long page) > @@ -3700,7 +3724,6 @@ void colo_flush_ram_cache(void) > void *src_host; > unsigned long offset = 0; > unsigned long num = 0; > - unsigned long i = 0; > > memory_global_dirty_log_sync(); > WITH_RCU_READ_LOCK_GUARD() { > @@ -3722,9 +3745,7 @@ void colo_flush_ram_cache(void) > num = 0; > block = QLIST_NEXT_RCU(block, next); > } else { > - for (i = 0; i < num; i++) { > - migration_bitmap_clear_dirty(ram_state, block, offset + i); > - } > + colo_bitmap_clear_dirty(ram_state, block, offset, num); > dst_host = block->host > + (((ram_addr_t)offset) << TARGET_PAGE_BITS); > src_host = block->colo_cache > -- > 1.8.3.1 > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK