From nobody Sat Feb 7 12:19:43 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=fail; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1642582510984787.6909139104359; Wed, 19 Jan 2022 00:55:10 -0800 (PST) Received: from localhost ([::1]:40420 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nA6kH-0001a4-CB for importer@patchew.org; Wed, 19 Jan 2022 03:55:09 -0500 Received: from eggs.gnu.org ([209.51.188.92]:58788) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nA62i-00072W-3U for qemu-devel@nongnu.org; Wed, 19 Jan 2022 03:10:08 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:24796) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nA62f-0000zt-R3 for qemu-devel@nongnu.org; Wed, 19 Jan 2022 03:10:07 -0500 Received: from mail-wm1-f70.google.com (mail-wm1-f70.google.com [209.85.128.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-247-1bKFoq8AO-mmyw_7Dh5MxA-1; Wed, 19 Jan 2022 03:10:03 -0500 Received: by mail-wm1-f70.google.com with SMTP id f7-20020a1cc907000000b0034b63f314ccso1328196wmb.6 for ; Wed, 19 Jan 2022 00:10:02 -0800 (PST) Received: from localhost.localdomain ([85.203.46.175]) by smtp.gmail.com with ESMTPSA id a20sm4351606wmb.27.2022.01.19.00.09.57 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Wed, 19 Jan 2022 00:10:00 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1642579804; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ZgXSsm4TobC9VeROQOkPev+2EEsMYK5pH9blVW1j0Ww=; b=c4mmYXlj8eB/jv/+qPIXWOOz1TyY8eK60W2UcC4In/Gn2DNFXmZVcmo3QAiuJviBITcycB xKMEhhg5BmdRzvLZy/Xl+rmC6ZIM/HHBo9eoL1n++LZWd+jpLBL5qtmN/0yyxbf79ZmXmr qZDyt55rt4Rh2fH2od09bSRbjh5VPnM= X-MC-Unique: 1bKFoq8AO-mmyw_7Dh5MxA-1 X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=ZgXSsm4TobC9VeROQOkPev+2EEsMYK5pH9blVW1j0Ww=; b=jqjGAaoTS7SmSfXhxTRhc1lz+jR+aGT8T1f8NTmIIpWbZ/pvVDNRbQPZ+23hxgNjvP 4KF7wJpIPlqnHQie0Gc3LqWXxgngDeKZkgGL7N7ZReF7tZWxu/KkI2hFxl1m7CiGSqOW 5t5ur/Q8h6tWX7pjRcFJUcFQRafUmGZaoI0afGtOroNbr0ExNf62UOfb00r+fTNuAN1e xpMlraNNBIvMnl50LS+/cG+yxmX/V+qBV97qivan2nIppPaZUyOMmVffnjdHXYCZUQQz aN52Q7wkH0yrK6UFOH1aBA7/QcuJQrvQ9SgzsYiYgIWz9iyoMOgnpQzG+dDjXULpPqan FNdQ== X-Gm-Message-State: AOAM531ZeWHz1S24afYuL5lpvBfigFBJnXKDLBkYBgMNE81LOsu9kt6y tCocpjk1oIKY7B3OYQljxtYcJsEZJwG1/62NCJbz2O6FaXGn++eK8Iuv5DAHVONpys1VDiuqNBA cRiU3ANXA/t0B09aABIWVIyir4uIv1cqsWID8/Ubil7Jug5idmZuENec6yubeReis X-Received: by 2002:a5d:4ad2:: with SMTP id y18mr27753902wrs.141.1642579801528; Wed, 19 Jan 2022 00:10:01 -0800 (PST) X-Google-Smtp-Source: ABdhPJz9HNYyGr7BYHOnFdIxA2U9phmfkzn7k9/TNtuzKUXOKkGo/c9ZyY6ZR0yQMzSpP2DjeCDm3w== X-Received: by 2002:a5d:4ad2:: with SMTP id y18mr27753882wrs.141.1642579801277; Wed, 19 Jan 2022 00:10:01 -0800 (PST) From: Peter Xu To: qemu-devel@nongnu.org Subject: [PATCH RFC 05/15] migration: Simplify unqueue_page() Date: Wed, 19 Jan 2022 16:09:19 +0800 Message-Id: <20220119080929.39485-6-peterx@redhat.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220119080929.39485-1-peterx@redhat.com> References: <20220119080929.39485-1-peterx@redhat.com> MIME-Version: 1.0 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=peterx@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=170.10.129.124; envelope-from=peterx@redhat.com; helo=us-smtp-delivery-124.mimecast.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, DKIMWL_WL_HIGH=-0.7, 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_H3=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: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Juan Quintela , "Dr . David Alan Gilbert" , peterx@redhat.com, Leonardo Bras Soares Passos Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) X-ZM-MESSAGEID: 1642582512870100001 Content-Type: text/plain; charset="utf-8" This patch simplifies unqueue_page() on both sides of it (itself, and calle= r). Firstly, due to the fact that right after unqueue_page() returned true, we'= ll definitely send a huge page (see ram_save_huge_page() call - it will _never_ exit before finish sending that huge page), so unqueue_page() does not need= to jump in small page size if huge page is enabled on the ramblock. IOW, it's destined that only the 1st 4K page will be valid, when unqueue the 2nd+ time we'll notice the whole huge page has already been sent anyway. Switching to operating on huge page reduces a lot of the loops of redundant unqueue_page= (). Meanwhile, drop the dirty check. It's not helpful to call test_bit() every time to jump over clean pages, as ram_save_host_page() has already done so, while in a faster way (see commit ba1b7c812c ("migration/ram: Optimize ram_save_host_page()", 2021-05-13)). So that's not necessary too. Drop the two tracepoints along the way - based on above analysis it's very possible that no one is really using it.. Signed-off-by: Peter Xu Reviewed-by: Dr. David Alan Gilbert Reviewed-by: Juan Quintela --- migration/ram.c | 34 ++++++++-------------------------- migration/trace-events | 2 -- 2 files changed, 8 insertions(+), 28 deletions(-) diff --git a/migration/ram.c b/migration/ram.c index dc6ba041fa..0df15ff663 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -1541,6 +1541,7 @@ static RAMBlock *unqueue_page(RAMState *rs, ram_addr_= t *offset) { struct RAMSrcPageRequest *entry; RAMBlock *block =3D NULL; + size_t page_size; =20 if (!postcopy_has_request(rs)) { return NULL; @@ -1557,10 +1558,13 @@ static RAMBlock *unqueue_page(RAMState *rs, ram_add= r_t *offset) entry =3D QSIMPLEQ_FIRST(&rs->src_page_requests); block =3D entry->rb; *offset =3D entry->offset; + page_size =3D qemu_ram_pagesize(block); + /* Each page request should only be multiple page size of the ramblock= */ + assert((entry->len % page_size) =3D=3D 0); =20 - if (entry->len > TARGET_PAGE_SIZE) { - entry->len -=3D TARGET_PAGE_SIZE; - entry->offset +=3D TARGET_PAGE_SIZE; + if (entry->len > page_size) { + entry->len -=3D page_size; + entry->offset +=3D page_size; } else { memory_region_unref(block->mr); QSIMPLEQ_REMOVE_HEAD(&rs->src_page_requests, next_req); @@ -1942,30 +1946,8 @@ static bool get_queued_page(RAMState *rs, PageSearch= Status *pss) { RAMBlock *block; ram_addr_t offset; - bool dirty; =20 - do { - block =3D unqueue_page(rs, &offset); - /* - * We're sending this page, and since it's postcopy nothing else - * will dirty it, and we must make sure it doesn't get sent again - * even if this queue request was received after the background - * search already sent it. - */ - if (block) { - unsigned long page; - - page =3D offset >> TARGET_PAGE_BITS; - dirty =3D test_bit(page, block->bmap); - if (!dirty) { - trace_get_queued_page_not_dirty(block->idstr, (uint64_t)of= fset, - page); - } else { - trace_get_queued_page(block->idstr, (uint64_t)offset, page= ); - } - } - - } while (block && !dirty); + block =3D unqueue_page(rs, &offset); =20 if (!block) { /* diff --git a/migration/trace-events b/migration/trace-events index e165687af2..3a9b3567ae 100644 --- a/migration/trace-events +++ b/migration/trace-events @@ -85,8 +85,6 @@ put_qlist_end(const char *field_name, const char *vmsd_na= me) "%s(%s)" qemu_file_fclose(void) "" =20 # ram.c -get_queued_page(const char *block_name, uint64_t tmp_offset, unsigned long= page_abs) "%s/0x%" PRIx64 " page_abs=3D0x%lx" -get_queued_page_not_dirty(const char *block_name, uint64_t tmp_offset, uns= igned long page_abs) "%s/0x%" PRIx64 " page_abs=3D0x%lx" migration_bitmap_sync_start(void) "" migration_bitmap_sync_end(uint64_t dirty_pages) "dirty_pages %" PRIu64 migration_bitmap_clear_dirty(char *str, uint64_t start, uint64_t size, uns= igned long page) "rb %s start 0x%"PRIx64" size 0x%"PRIx64" page 0x%lx" --=20 2.32.0