From patchwork Mon Apr 13 10:15:08 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Keqian Zhu X-Patchwork-Id: 1269761 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=huawei.com 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 ozlabs.org (Postfix) with ESMTPS id 4914MW4rXqz9sSY for ; Mon, 13 Apr 2020 20:18:31 +1000 (AEST) Received: from localhost ([::1]:42604 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jNwAf-0006nV-B1 for incoming@patchwork.ozlabs.org; Mon, 13 Apr 2020 06:18:29 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:54186) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jNwA1-0006j6-N0 for qemu-devel@nongnu.org; Mon, 13 Apr 2020 06:17:51 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1jNw9z-0007oN-Tt for qemu-devel@nongnu.org; Mon, 13 Apr 2020 06:17:49 -0400 Received: from szxga06-in.huawei.com ([45.249.212.32]:38954 helo=huawei.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1jNw9n-0007gp-25; Mon, 13 Apr 2020 06:17:37 -0400 Received: from DGGEMS404-HUB.china.huawei.com (unknown [172.30.72.60]) by Forcepoint Email with ESMTP id 978F240315464F5E7FE3; Mon, 13 Apr 2020 18:17:29 +0800 (CST) Received: from linux-kDCJWP.huawei.com (10.175.104.212) by DGGEMS404-HUB.china.huawei.com (10.3.19.204) with Microsoft SMTP Server id 14.3.487.0; Mon, 13 Apr 2020 18:17:21 +0800 From: Keqian Zhu To: Subject: [PATCH v3] migration/throttle: Add cpu-throttle-tailslow migration parameter Date: Mon, 13 Apr 2020 18:15:08 +0800 Message-ID: <20200413101508.54793-1-zhukeqian1@huawei.com> X-Mailer: git-send-email 2.19.1 MIME-Version: 1.0 X-Originating-IP: [10.175.104.212] X-CFilter-Loop: Reflected X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 45.249.212.32 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: Juan Quintela , "Dr. David Alan Gilbert" , Markus Armbruster , qemu-arm@nongnu.org, wanghaibin.wang@huawei.com, Keqian Zhu Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" At the tail stage of throttling, the Guest is very sensitive to CPU percentage while the @cpu-throttle-increment is excessive usually at tail stage. If this parameter is true, we will compute the ideal CPU percentage used by the Guest, which may exactly make the dirty rate match the dirty rate threshold. Then we will choose a smaller throttle increment between the one specified by @cpu-throttle-increment and the one generated by ideal CPU percentage. Therefore, it is compatible to traditional throttling, meanwhile the throttle increment won't be excessive at tail stage. This may make migration time longer, and is disabled by default. Signed-off-by: Keqian Zhu Reviewed-by: Dr. David Alan Gilbert --- Cc: Juan Quintela Cc: "Dr. David Alan Gilbert" Cc: Eric Blake Cc: Markus Armbruster --- migration/migration.c | 13 ++++++++++++ migration/ram.c | 25 +++++++++++++++++----- monitor/hmp-cmds.c | 8 ++++++++ qapi/migration.json | 48 +++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 89 insertions(+), 5 deletions(-) diff --git a/migration/migration.c b/migration/migration.c index 187ac0410c..d478a87290 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -785,6 +785,8 @@ MigrationParameters *qmp_query_migrate_parameters(Error **errp) params->cpu_throttle_initial = s->parameters.cpu_throttle_initial; params->has_cpu_throttle_increment = true; params->cpu_throttle_increment = s->parameters.cpu_throttle_increment; + params->has_cpu_throttle_tailslow = true; + params->cpu_throttle_tailslow = s->parameters.cpu_throttle_tailslow; params->has_tls_creds = true; params->tls_creds = g_strdup(s->parameters.tls_creds); params->has_tls_hostname = true; @@ -1324,6 +1326,10 @@ static void migrate_params_test_apply(MigrateSetParameters *params, dest->cpu_throttle_increment = params->cpu_throttle_increment; } + if (params->has_cpu_throttle_tailslow) { + dest->cpu_throttle_tailslow = params->cpu_throttle_tailslow; + } + if (params->has_tls_creds) { assert(params->tls_creds->type == QTYPE_QSTRING); dest->tls_creds = g_strdup(params->tls_creds->u.s); @@ -1412,6 +1418,10 @@ static void migrate_params_apply(MigrateSetParameters *params, Error **errp) s->parameters.cpu_throttle_increment = params->cpu_throttle_increment; } + if (params->has_cpu_throttle_tailslow) { + s->parameters.cpu_throttle_tailslow = params->cpu_throttle_tailslow; + } + if (params->has_tls_creds) { g_free(s->parameters.tls_creds); assert(params->tls_creds->type == QTYPE_QSTRING); @@ -3594,6 +3604,8 @@ static Property migration_properties[] = { DEFINE_PROP_UINT8("x-cpu-throttle-increment", MigrationState, parameters.cpu_throttle_increment, DEFAULT_MIGRATE_CPU_THROTTLE_INCREMENT), + DEFINE_PROP_BOOL("x-cpu-throttle-tailslow", MigrationState, + parameters.cpu_throttle_tailslow, false), DEFINE_PROP_SIZE("x-max-bandwidth", MigrationState, parameters.max_bandwidth, MAX_THROTTLE), DEFINE_PROP_UINT64("x-downtime-limit", MigrationState, @@ -3700,6 +3712,7 @@ static void migration_instance_init(Object *obj) params->has_throttle_trigger_threshold = true; params->has_cpu_throttle_initial = true; params->has_cpu_throttle_increment = true; + params->has_cpu_throttle_tailslow = true; params->has_max_bandwidth = true; params->has_downtime_limit = true; params->has_x_checkpoint_delay = true; diff --git a/migration/ram.c b/migration/ram.c index 04f13feb2e..3317c99786 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -616,20 +616,34 @@ static size_t save_page_header(RAMState *rs, QEMUFile *f, RAMBlock *block, * able to complete migration. Some workloads dirty memory way too * fast and will not effectively converge, even with auto-converge. */ -static void mig_throttle_guest_down(void) +static void mig_throttle_guest_down(uint64_t bytes_dirty_period, + uint64_t bytes_dirty_threshold) { MigrationState *s = migrate_get_current(); uint64_t pct_initial = s->parameters.cpu_throttle_initial; - uint64_t pct_icrement = s->parameters.cpu_throttle_increment; + uint64_t pct_increment = s->parameters.cpu_throttle_increment; + bool pct_tailslow = s->parameters.cpu_throttle_tailslow; int pct_max = s->parameters.max_cpu_throttle; + uint64_t throttle_now = cpu_throttle_get_percentage(); + uint64_t cpu_now, cpu_ideal, throttle_inc; + /* We have not started throttling yet. Let's start it. */ if (!cpu_throttle_active()) { cpu_throttle_set(pct_initial); } else { /* Throttling already on, just increase the rate */ - cpu_throttle_set(MIN(cpu_throttle_get_percentage() + pct_icrement, - pct_max)); + if (!pct_tailslow) { + throttle_inc = pct_increment; + } else { + /* Compute the ideal CPU percentage used by Guest, which may + * make the dirty rate match the dirty rate threshold. */ + cpu_now = 100 - throttle_now; + cpu_ideal = cpu_now * (bytes_dirty_threshold * 1.0 / + bytes_dirty_period); + throttle_inc = MIN(cpu_now - cpu_ideal, pct_increment); + } + cpu_throttle_set(MIN(throttle_now + throttle_inc, pct_max)); } } @@ -919,7 +933,8 @@ static void migration_trigger_throttle(RAMState *rs) (++rs->dirty_rate_high_cnt >= 2)) { trace_migration_throttle(); rs->dirty_rate_high_cnt = 0; - mig_throttle_guest_down(); + mig_throttle_guest_down(bytes_dirty_period, + bytes_dirty_threshold); } } } diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c index 9b94e67879..acd7539273 100644 --- a/monitor/hmp-cmds.c +++ b/monitor/hmp-cmds.c @@ -419,6 +419,10 @@ void hmp_info_migrate_parameters(Monitor *mon, const QDict *qdict) monitor_printf(mon, "%s: %u\n", MigrationParameter_str(MIGRATION_PARAMETER_CPU_THROTTLE_INCREMENT), params->cpu_throttle_increment); + assert(params->has_cpu_throttle_tailslow); + monitor_printf(mon, "%s: %s\n", + MigrationParameter_str(MIGRATION_PARAMETER_CPU_THROTTLE_TAILSLOW), + params->cpu_throttle_tailslow ? "on" : "off"); assert(params->has_max_cpu_throttle); monitor_printf(mon, "%s: %u\n", MigrationParameter_str(MIGRATION_PARAMETER_MAX_CPU_THROTTLE), @@ -1271,6 +1275,10 @@ void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict) p->has_cpu_throttle_increment = true; visit_type_int(v, param, &p->cpu_throttle_increment, &err); break; + case MIGRATION_PARAMETER_CPU_THROTTLE_TAILSLOW: + p->has_cpu_throttle_tailslow = true; + visit_type_bool(v, param, &p->cpu_throttle_tailslow, &err); + break; case MIGRATION_PARAMETER_MAX_CPU_THROTTLE: p->has_max_cpu_throttle = true; visit_type_int(v, param, &p->max_cpu_throttle, &err); diff --git a/qapi/migration.json b/qapi/migration.json index eca2981d0a..ee6c5a0cae 100644 --- a/qapi/migration.json +++ b/qapi/migration.json @@ -552,6 +552,21 @@ # auto-converge detects that migration is not making # progress. The default value is 10. (Since 2.7) # +# @cpu-throttle-tailslow: Make CPU throttling slower at tail stage +# At the tail stage of throttling, the Guest is very +# sensitive to CPU percentage while the @cpu-throttle +# -increment is excessive usually at tail stage. +# If this parameter is true, we will compute the ideal +# CPU percentage used by the Guest, which may exactly make +# the dirty rate match the dirty rate threshold. Then we +# will choose a smaller throttle increment between the +# one specified by @cpu-throttle-increment and the one +# generated by ideal CPU percentage. +# Therefore, it is compatible to traditional throttling, +# meanwhile the throttle increment won't be excessive +# at tail stage. +# The default value is false. (Since 5.1) +# # @tls-creds: ID of the 'tls-creds' object that provides credentials for # establishing a TLS connection over the migration data channel. # On the outgoing side of the migration, the credentials must @@ -631,6 +646,7 @@ 'compress-level', 'compress-threads', 'decompress-threads', 'compress-wait-thread', 'throttle-trigger-threshold', 'cpu-throttle-initial', 'cpu-throttle-increment', + 'cpu-throttle-tailslow', 'tls-creds', 'tls-hostname', 'tls-authz', 'max-bandwidth', 'downtime-limit', 'x-checkpoint-delay', 'block-incremental', 'multifd-channels', @@ -676,6 +692,21 @@ # auto-converge detects that migration is not making # progress. The default value is 10. (Since 2.7) # +# @cpu-throttle-tailslow: Make CPU throttling slower at tail stage +# At the tail stage of throttling, the Guest is very +# sensitive to CPU percentage while the @cpu-throttle +# -increment is excessive usually at tail stage. +# If this parameter is true, we will compute the ideal +# CPU percentage used by the Guest, which may exactly make +# the dirty rate match the dirty rate threshold. Then we +# will choose a smaller throttle increment between the +# one specified by @cpu-throttle-increment and the one +# generated by ideal CPU percentage. +# Therefore, it is compatible to traditional throttling, +# meanwhile the throttle increment won't be excessive +# at tail stage. +# The default value is false. (Since 5.1) +# # @tls-creds: ID of the 'tls-creds' object that provides credentials # for establishing a TLS connection over the migration data # channel. On the outgoing side of the migration, the credentials @@ -763,6 +794,7 @@ '*throttle-trigger-threshold': 'int', '*cpu-throttle-initial': 'int', '*cpu-throttle-increment': 'int', + '*cpu-throttle-tailslow': 'bool', '*tls-creds': 'StrOrNull', '*tls-hostname': 'StrOrNull', '*tls-authz': 'StrOrNull', @@ -834,6 +866,21 @@ # auto-converge detects that migration is not making # progress. (Since 2.7) # +# @cpu-throttle-tailslow: Make CPU throttling slower at tail stage +# At the tail stage of throttling, the Guest is very +# sensitive to CPU percentage while the @cpu-throttle +# -increment is excessive usually at tail stage. +# If this parameter is true, we will compute the ideal +# CPU percentage used by the Guest, which may exactly make +# the dirty rate match the dirty rate threshold. Then we +# will choose a smaller throttle increment between the +# one specified by @cpu-throttle-increment and the one +# generated by ideal CPU percentage. +# Therefore, it is compatible to traditional throttling, +# meanwhile the throttle increment won't be excessive +# at tail stage. +# The default value is false. (Since 5.1) +# # @tls-creds: ID of the 'tls-creds' object that provides credentials # for establishing a TLS connection over the migration data # channel. On the outgoing side of the migration, the credentials @@ -921,6 +968,7 @@ '*throttle-trigger-threshold': 'uint8', '*cpu-throttle-initial': 'uint8', '*cpu-throttle-increment': 'uint8', + '*cpu-throttle-tailslow': 'bool', '*tls-creds': 'str', '*tls-hostname': 'str', '*tls-authz': 'str',