From patchwork Thu Apr 30 00:59:35 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Wang, Wei W" X-Patchwork-Id: 11519055 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id EB2C792A for ; Thu, 30 Apr 2020 01:54:22 +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 81C462082E for ; Thu, 30 Apr 2020 01:54:22 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 81C462082E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Received: from localhost ([::1]:43562 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jTyP7-0004f5-BS for patchwork-qemu-devel@patchwork.kernel.org; Wed, 29 Apr 2020 21:54:21 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:35622) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jTyOg-0004GS-C9 for qemu-devel@nongnu.org; Wed, 29 Apr 2020 21:53:54 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.90_1) (envelope-from ) id 1jTyOe-0007Ex-M3 for qemu-devel@nongnu.org; Wed, 29 Apr 2020 21:53:53 -0400 Received: from mga17.intel.com ([192.55.52.151]:46011) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jTyOe-0007Ec-4g for qemu-devel@nongnu.org; Wed, 29 Apr 2020 21:53:52 -0400 IronPort-SDR: a5XSvhW8BczX0FwkNDACqBT9Tu/wp7o6aw5lcfsqogy/3Y8oAsjC4+/QyObkK85Z+3kdoOMpXi uNGmVpS83RAQ== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Apr 2020 18:53:43 -0700 IronPort-SDR: E0nw1rKUWXwuIfqqP5uib1vp6j7gsMEBTaq1rbIoYmoa0chLAx1t3KGHsROmqKutQCFsxu5jwB JuFfLRE9goVA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,333,1583222400"; d="scan'208";a="459397216" Received: from devel-ww.sh.intel.com ([10.239.48.118]) by fmsmga005.fm.intel.com with ESMTP; 29 Apr 2020 18:53:41 -0700 From: Wei Wang To: qemu-devel@nongnu.org, quintela@redhat.com, dgilbert@redhat.com, peterx@redhat.com Subject: [PATCH v3] migration/xbzrle: add encoding rate Date: Thu, 30 Apr 2020 08:59:35 +0800 Message-Id: <1588208375-19556-1-git-send-email-wei.w.wang@intel.com> X-Mailer: git-send-email 2.7.4 Received-SPF: pass client-ip=192.55.52.151; envelope-from=wei.w.wang@intel.com; helo=mga17.intel.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/04/29 21:53:44 X-ACL-Warn: Detected OS = FreeBSD 9.x or newer [fuzzy] X-Received-From: 192.55.52.151 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: gloryxiao@tencent.com, kevin.tian@intel.com, wei.w.wang@intel.com, yi.y.sun@intel.com Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" Users may need to check the xbzrle encoding rate to know if the guest memory is xbzrle encoding-friendly, and dynamically turn off the encoding if the encoding rate is low. Signed-off-by: Yi Sun Signed-off-by: Wei Wang Reviewed-by: Dr. David Alan Gilbert --- migration/migration.c | 1 + migration/ram.c | 39 +++++++++++++++++++++++++++++++++++++-- monitor/hmp-cmds.c | 2 ++ qapi/migration.json | 5 ++++- 4 files changed, 44 insertions(+), 3 deletions(-) diff --git a/migration/migration.c b/migration/migration.c index 187ac0410c..e40421353c 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -930,6 +930,7 @@ static void populate_ram_info(MigrationInfo *info, MigrationState *s) info->xbzrle_cache->pages = xbzrle_counters.pages; info->xbzrle_cache->cache_miss = xbzrle_counters.cache_miss; info->xbzrle_cache->cache_miss_rate = xbzrle_counters.cache_miss_rate; + info->xbzrle_cache->encoding_rate = xbzrle_counters.encoding_rate; info->xbzrle_cache->overflow = xbzrle_counters.overflow; } diff --git a/migration/ram.c b/migration/ram.c index 04f13feb2e..41b75a0a0f 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -327,6 +327,10 @@ struct RAMState { uint64_t num_dirty_pages_period; /* xbzrle misses since the beginning of the period */ uint64_t xbzrle_cache_miss_prev; + /* Amount of xbzrle pages since the beginning of the period */ + uint64_t xbzrle_pages_prev; + /* Amount of xbzrle encoded bytes since the beginning of the period */ + uint64_t xbzrle_bytes_prev; /* compression statistics since the beginning of the period */ /* amount of count that no free thread to compress data */ @@ -696,6 +700,18 @@ static int save_xbzrle_page(RAMState *rs, uint8_t **current_data, return -1; } + /* + * Reaching here means the page has hit the xbzrle cache, no matter what + * encoding result it is (normal encoding, overflow or skipping the page), + * count the page as encoded. This is used to caculate the encoding rate. + * + * Example: 2 pages (8KB) being encoded, first page encoding generates 2KB, + * 2nd page turns out to be skipped (i.e. no new bytes written to the + * page), the overall encoding rate will be 8KB / 2KB = 4, which has the + * skipped page included. In this way, the encoding rate can tell if the + * guest page is good for xbzrle encoding. + */ + xbzrle_counters.pages++; prev_cached_page = get_cached_data(XBZRLE.cache, current_addr); /* save current buffer into memory */ @@ -726,6 +742,7 @@ static int save_xbzrle_page(RAMState *rs, uint8_t **current_data, } else if (encoded_len == -1) { trace_save_xbzrle_page_overflow(); xbzrle_counters.overflow++; + xbzrle_counters.bytes += TARGET_PAGE_SIZE; return -1; } @@ -736,8 +753,12 @@ static int save_xbzrle_page(RAMState *rs, uint8_t **current_data, qemu_put_be16(rs->f, encoded_len); qemu_put_buffer(rs->f, XBZRLE.encoded_buf, encoded_len); bytes_xbzrle += encoded_len + 1 + 2; - xbzrle_counters.pages++; - xbzrle_counters.bytes += bytes_xbzrle; + /* + * Like compressed_size (please see update_compress_thread_counts), + * the xbzrle encoded bytes don't count the 8 byte header with + * RAM_SAVE_FLAG_CONTINUE. + */ + xbzrle_counters.bytes += bytes_xbzrle - 8; ram_counters.transferred += bytes_xbzrle; return 1; @@ -870,9 +891,23 @@ static void migration_update_rates(RAMState *rs, int64_t end_time) } if (migrate_use_xbzrle()) { + double encoded_size, unencoded_size; + xbzrle_counters.cache_miss_rate = (double)(xbzrle_counters.cache_miss - rs->xbzrle_cache_miss_prev) / page_count; rs->xbzrle_cache_miss_prev = xbzrle_counters.cache_miss; + unencoded_size = (xbzrle_counters.pages - rs->xbzrle_pages_prev) * + TARGET_PAGE_SIZE; + encoded_size = xbzrle_counters.bytes - rs->xbzrle_bytes_prev; + if (xbzrle_counters.pages == rs->xbzrle_pages_prev) { + xbzrle_counters.encoding_rate = 0; + } else if (!encoded_size) { + xbzrle_counters.encoding_rate = UINT64_MAX; + } else { + xbzrle_counters.encoding_rate = unencoded_size / encoded_size; + } + rs->xbzrle_pages_prev = xbzrle_counters.pages; + rs->xbzrle_bytes_prev = xbzrle_counters.bytes; } if (migrate_use_compression()) { diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c index 9b94e67879..c2a3a667ae 100644 --- a/monitor/hmp-cmds.c +++ b/monitor/hmp-cmds.c @@ -303,6 +303,8 @@ void hmp_info_migrate(Monitor *mon, const QDict *qdict) info->xbzrle_cache->cache_miss); monitor_printf(mon, "xbzrle cache miss rate: %0.2f\n", info->xbzrle_cache->cache_miss_rate); + monitor_printf(mon, "xbzrle encoding rate: %0.2f\n", + info->xbzrle_cache->encoding_rate); monitor_printf(mon, "xbzrle overflow: %" PRIu64 "\n", info->xbzrle_cache->overflow); } diff --git a/qapi/migration.json b/qapi/migration.json index eca2981d0a..358e40226d 100644 --- a/qapi/migration.json +++ b/qapi/migration.json @@ -70,6 +70,8 @@ # # @cache-miss-rate: rate of cache miss (since 2.1) # +# @encoding-rate: rate of encoded bytes (since 5.1) +# # @overflow: number of overflows # # Since: 1.2 @@ -77,7 +79,7 @@ { 'struct': 'XBZRLECacheStats', 'data': {'cache-size': 'int', 'bytes': 'int', 'pages': 'int', 'cache-miss': 'int', 'cache-miss-rate': 'number', - 'overflow': 'int' } } + 'encoding-rate': 'number', 'overflow': 'int' } } ## # @CompressionStats: @@ -337,6 +339,7 @@ # "pages":2444343, # "cache-miss":2244, # "cache-miss-rate":0.123, +# "encoding-rate":80.1, # "overflow":34434 # } # }