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=-13.6 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 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 E4FA0C433B4 for ; Tue, 18 May 2021 10:21:07 +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 7E82F60BD3 for ; Tue, 18 May 2021 10:21:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7E82F60BD3 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]:41902 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1liwqY-0006dW-MS for qemu-devel@archiver.kernel.org; Tue, 18 May 2021 06:21:06 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:43010) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1liweD-0002mS-W2 for qemu-devel@nongnu.org; Tue, 18 May 2021 06:08:22 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:27997) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1liweB-0007h5-VH for qemu-devel@nongnu.org; Tue, 18 May 2021 06:08:21 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1621332499; 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=9lZ83aft9SpgzX0qL/+FL99/aJ1UNdMSfOcWCB4ES+I=; b=NxdS06Srx5aZFfAwxNRPJJYPP9MSWJaO8sOlznwN8UYkW8h6vJkOzIsLAbEipb2NA3PdAd +T7J7oDm5sZzjcOpHB5R8+hyVUfNukxS6mOHfyuZp+kdu3eipVuc9cl2vcpU8rC5ksnrKv 1uypXRjoFNiBUDkRZsKHQgTP7VTNFzE= 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-167--cQIQgs_NDu03ZIDUQy-RA-1; Tue, 18 May 2021 06:08:17 -0400 X-MC-Unique: -cQIQgs_NDu03ZIDUQy-RA-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id D41E3100747E; Tue, 18 May 2021 10:08:15 +0000 (UTC) Received: from localhost.localdomain (ovpn-114-236.ams2.redhat.com [10.36.114.236]) by smtp.corp.redhat.com (Postfix) with ESMTP id 340BC687C1; Tue, 18 May 2021 10:08:05 +0000 (UTC) From: Emanuele Giuseppe Esposito To: qemu-block@nongnu.org Subject: [PATCH v2 1/7] block-copy: streamline choice of copy_range vs. read/write Date: Tue, 18 May 2021 12:07:51 +0200 Message-Id: <20210518100757.31243-2-eesposit@redhat.com> In-Reply-To: <20210518100757.31243-1-eesposit@redhat.com> References: <20210518100757.31243-1-eesposit@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=eesposit@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="US-ASCII" Received-SPF: pass client-ip=216.205.24.124; envelope-from=eesposit@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -31 X-Spam_score: -3.2 X-Spam_bar: --- X-Spam_report: (-3.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.374, 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: Kevin Wolf , Emanuele Giuseppe Esposito , Vladimir Sementsov-Ogievskiy , qemu-devel@nongnu.org, Max Reitz , Stefan Hajnoczi , Paolo Bonzini , John Snow Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Paolo Bonzini Put the logic to determine the copy size in a separate function, so that there is a simple state machine for the possible methods of copying data from one BlockDriverState to the other. While at it, store the common computation of block_copy_max_transfer into a new field of BlockCopyState, and make sure that we always obey max_transfer; that's more efficient even for the COPY_RANGE_READ_WRITE case. Signed-off-by: Emanuele Giuseppe Esposito Signed-off-by: Paolo Bonzini --- block/block-copy.c | 59 ++++++++++++++++++++++++++++++---------------- 1 file changed, 39 insertions(+), 20 deletions(-) diff --git a/block/block-copy.c b/block/block-copy.c index 37c8e8504b..10ce51a244 100644 --- a/block/block-copy.c +++ b/block/block-copy.c @@ -28,6 +28,13 @@ #define BLOCK_COPY_MAX_WORKERS 64 #define BLOCK_COPY_SLICE_TIME 100000000ULL /* ns */ +typedef enum { + COPY_READ_WRITE_CLUSTER, + COPY_READ_WRITE, + COPY_RANGE_SMALL, + COPY_RANGE_FULL +} BlockCopyMethod; + static coroutine_fn int block_copy_task_entry(AioTask *task); typedef struct BlockCopyCallState { @@ -85,8 +92,8 @@ typedef struct BlockCopyState { BdrvDirtyBitmap *copy_bitmap; int64_t in_flight_bytes; int64_t cluster_size; - bool use_copy_range; - int64_t copy_size; + BlockCopyMethod method; + int64_t max_transfer; uint64_t len; QLIST_HEAD(, BlockCopyTask) tasks; /* All tasks from all block-copy calls */ QLIST_HEAD(, BlockCopyCallState) calls; @@ -148,6 +155,23 @@ static bool coroutine_fn block_copy_wait_one(BlockCopyState *s, int64_t offset, return true; } +static inline int64_t block_copy_chunk_size(BlockCopyState *s) +{ + switch (s->method) { + case COPY_READ_WRITE_CLUSTER: + return s->cluster_size; + case COPY_READ_WRITE: + case COPY_RANGE_SMALL: + return MIN(MAX(s->cluster_size, BLOCK_COPY_MAX_BUFFER), + s->max_transfer); + case COPY_RANGE_FULL: + return MIN(MAX(s->cluster_size, BLOCK_COPY_MAX_COPY_RANGE), + s->max_transfer); + default: + abort(); + } +} + /* * Search for the first dirty area in offset/bytes range and create task at * the beginning of it. @@ -157,8 +181,9 @@ static BlockCopyTask *block_copy_task_create(BlockCopyState *s, int64_t offset, int64_t bytes) { BlockCopyTask *task; - int64_t max_chunk = MIN_NON_ZERO(s->copy_size, call_state->max_chunk); + int64_t max_chunk = block_copy_chunk_size(s); + max_chunk = MIN_NON_ZERO(max_chunk, call_state->max_chunk); if (!bdrv_dirty_bitmap_next_dirty_area(s->copy_bitmap, offset, offset + bytes, max_chunk, &offset, &bytes)) @@ -265,28 +290,27 @@ BlockCopyState *block_copy_state_new(BdrvChild *source, BdrvChild *target, .len = bdrv_dirty_bitmap_size(copy_bitmap), .write_flags = write_flags, .mem = shres_create(BLOCK_COPY_MAX_MEM), + .max_transfer = QEMU_ALIGN_DOWN(block_copy_max_transfer(source, target) + , cluster_size), }; - if (block_copy_max_transfer(source, target) < cluster_size) { + if (s->max_transfer < cluster_size) { /* * copy_range does not respect max_transfer. We don't want to bother * with requests smaller than block-copy cluster size, so fallback to * buffered copying (read and write respect max_transfer on their * behalf). */ - s->use_copy_range = false; - s->copy_size = cluster_size; + s->method = COPY_READ_WRITE_CLUSTER; } else if (write_flags & BDRV_REQ_WRITE_COMPRESSED) { /* Compression supports only cluster-size writes and no copy-range. */ - s->use_copy_range = false; - s->copy_size = cluster_size; + s->method = COPY_READ_WRITE_CLUSTER; } else { /* * We enable copy-range, but keep small copy_size, until first * successful copy_range (look at block_copy_do_copy). */ - s->use_copy_range = use_copy_range; - s->copy_size = MAX(s->cluster_size, BLOCK_COPY_MAX_BUFFER); + s->method = use_copy_range ? COPY_RANGE_SMALL : COPY_READ_WRITE; } ratelimit_init(&s->rate_limit); @@ -369,30 +393,25 @@ static int coroutine_fn block_copy_do_copy(BlockCopyState *s, return ret; } - if (s->use_copy_range) { + if (s->method >= COPY_RANGE_SMALL) { ret = bdrv_co_copy_range(s->source, offset, s->target, offset, nbytes, 0, s->write_flags); if (ret < 0) { trace_block_copy_copy_range_fail(s, offset, ret); - s->use_copy_range = false; - s->copy_size = MAX(s->cluster_size, BLOCK_COPY_MAX_BUFFER); + s->method = COPY_READ_WRITE; /* Fallback to read+write with allocated buffer */ } else { - if (s->use_copy_range) { + if (s->method == COPY_RANGE_SMALL) { /* * Successful copy-range. Now increase copy_size. copy_range * does not respect max_transfer (it's a TODO), so we factor * that in here. * - * Note: we double-check s->use_copy_range for the case when + * Note: we double-check s->method for the case when * parallel block-copy request unsets it during previous * bdrv_co_copy_range call. */ - s->copy_size = - MIN(MAX(s->cluster_size, BLOCK_COPY_MAX_COPY_RANGE), - QEMU_ALIGN_DOWN(block_copy_max_transfer(s->source, - s->target), - s->cluster_size)); + s->method = COPY_RANGE_FULL; } goto out; } -- 2.30.2