From nobody Thu Nov 13 09:08:58 2025 Delivered-To: importer@patchew.org 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; 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 ARC-Seal: i=1; a=rsa-sha256; t=1579006824; cv=none; d=zohomail.com; s=zohoarc; b=jFmvn58q0czmVJSb7BL7K4gUtRrspQjHvLvrJXCPG0cORNAAlR7oeVfL9fx9CWURw8ZI8xtYUQXNaNGKL21LfqV2ne77s1hR7h+lgFUimuHulpSmLZze66cf3sLWfdNGxG6k32aqX07zpYNRZiCN3OAQhBNR4Nu4yF7kAdnOHQU= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1579006824; h=Content-Type:Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To; bh=iGtOvyEUGfifsxxl01xh+gxn1N24J9QLDuYgx3ZYdPU=; b=VOTLblpzdeCfHAiAIvEpqvJK4ZEVW8IdNKCDoFlYgkwVKlyB31x8cpKEPwn0547+AwvgiFDsKExgvkfl9BfKC2fz7HZWXKK8OFFODtQgn2PYo8u2NGvs/LuEkjEWGhpGvlINbWpvd6W+ho6FLnhYAV0G+EGqNebLd5bKYXj7bpU= ARC-Authentication-Results: i=1; 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 header.from= (p=none dis=none) header.from= Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 157900682402239.073177863935484; Tue, 14 Jan 2020 05:00:24 -0800 (PST) Received: from localhost ([::1]:38918 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1irLny-0008Ia-0c for importer@patchew.org; Tue, 14 Jan 2020 08:00:22 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:40879) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1irLiL-0002AH-PY for qemu-devel@nongnu.org; Tue, 14 Jan 2020 07:54:35 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1irLiI-0001br-2Z for qemu-devel@nongnu.org; Tue, 14 Jan 2020 07:54:33 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:30583 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1irLiH-0001bj-Tz for qemu-devel@nongnu.org; Tue, 14 Jan 2020 07:54:30 -0500 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-128-y3znGWDzNZaSpFMACrMSDQ-1; Tue, 14 Jan 2020 07:54:27 -0500 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 1A3C9801E77; Tue, 14 Jan 2020 12:54:26 +0000 (UTC) Received: from secure.mitica (ovpn-116-207.ams2.redhat.com [10.36.116.207]) by smtp.corp.redhat.com (Postfix) with ESMTP id 165B95D9E5; Tue, 14 Jan 2020 12:54:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1579006469; 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=iGtOvyEUGfifsxxl01xh+gxn1N24J9QLDuYgx3ZYdPU=; b=I/JnRG/W/VjxN0U5DUQKGTCubqFx5Ew7k8D3B8/Zh5RLa4HYk/t91+fsu+mH+C+tfB5EC7 UAwwHX0DGQVOGnEgOlT5BKTW/xqjd/jLJF0E43+3vqZ+Tm77/U3moS2ZKAbmPqjl1CBpRe 9b7aTxRsG1VupCiyLLeZcByzhEzDO/g= From: Juan Quintela To: qemu-devel@nongnu.org Subject: [PULL 09/30] migration: Rate limit inside host pages Date: Tue, 14 Jan 2020 13:52:33 +0100 Message-Id: <20200114125254.4515-10-quintela@redhat.com> In-Reply-To: <20200114125254.4515-1-quintela@redhat.com> References: <20200114125254.4515-1-quintela@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-MC-Unique: y3znGWDzNZaSpFMACrMSDQ-1 X-Mimecast-Spam-Score: 0 Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 205.139.110.120 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: Peter Maydell , Corey Minyard , Jason Wang , Peter Xu , Juan Quintela , "Michael S. Tsirkin" , =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= , David Gibson , Laurent Vivier , Thomas Huth , Eduardo Habkost , Stefan Weil , "Dr. David Alan Gilbert" , qemu-arm@nongnu.org, Richard Henderson , =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= , qemu-ppc@nongnu.org, Lin Ma , Paolo Bonzini , Stefan Berger Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) Content-Type: text/plain; charset="utf-8" From: "Dr. David Alan Gilbert" When using hugepages, rate limiting is necessary within each huge page, since a 1G huge page can take a significant time to send, so you end up with bursty behaviour. Fixes: 4c011c37ecb3 ("postcopy: Send whole huge pages") Reported-by: Lin Ma Signed-off-by: Dr. David Alan Gilbert Reviewed-by: Juan Quintela Reviewed-by: Peter Xu Signed-off-by: Juan Quintela --- migration/migration.c | 57 ++++++++++++++++++++++++------------------ migration/migration.h | 1 + migration/ram.c | 2 ++ migration/trace-events | 4 +-- 4 files changed, 37 insertions(+), 27 deletions(-) diff --git a/migration/migration.c b/migration/migration.c index 354ad072fa..27500d09a9 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -3224,6 +3224,37 @@ void migration_consume_urgent_request(void) qemu_sem_wait(&migrate_get_current()->rate_limit_sem); } =20 +/* Returns true if the rate limiting was broken by an urgent request */ +bool migration_rate_limit(void) +{ + int64_t now =3D qemu_clock_get_ms(QEMU_CLOCK_REALTIME); + MigrationState *s =3D migrate_get_current(); + + bool urgent =3D false; + migration_update_counters(s, now); + if (qemu_file_rate_limit(s->to_dst_file)) { + /* + * Wait for a delay to do rate limiting OR + * something urgent to post the semaphore. + */ + int ms =3D s->iteration_start_time + BUFFER_DELAY - now; + trace_migration_rate_limit_pre(ms); + if (qemu_sem_timedwait(&s->rate_limit_sem, ms) =3D=3D 0) { + /* + * We were woken by one or more urgent things but + * the timedwait will have consumed one of them. + * The service routine for the urgent wake will dec + * the semaphore itself for each item it consumes, + * so add this one we just eat back. + */ + qemu_sem_post(&s->rate_limit_sem); + urgent =3D true; + } + trace_migration_rate_limit_post(urgent); + } + return urgent; +} + /* * Master migration thread on the source VM. * It drives the migration and pumps the data down the outgoing channel. @@ -3290,8 +3321,6 @@ static void *migration_thread(void *opaque) trace_migration_thread_setup_complete(); =20 while (migration_is_active(s)) { - int64_t current_time; - if (urgent || !qemu_file_rate_limit(s->to_dst_file)) { MigIterateState iter_state =3D migration_iteration_run(s); if (iter_state =3D=3D MIG_ITERATE_SKIP) { @@ -3318,29 +3347,7 @@ static void *migration_thread(void *opaque) update_iteration_initial_status(s); } =20 - current_time =3D qemu_clock_get_ms(QEMU_CLOCK_REALTIME); - - migration_update_counters(s, current_time); - - urgent =3D false; - if (qemu_file_rate_limit(s->to_dst_file)) { - /* Wait for a delay to do rate limiting OR - * something urgent to post the semaphore. - */ - int ms =3D s->iteration_start_time + BUFFER_DELAY - current_ti= me; - trace_migration_thread_ratelimit_pre(ms); - if (qemu_sem_timedwait(&s->rate_limit_sem, ms) =3D=3D 0) { - /* We were worken by one or more urgent things but - * the timedwait will have consumed one of them. - * The service routine for the urgent wake will dec - * the semaphore itself for each item it consumes, - * so add this one we just eat back. - */ - qemu_sem_post(&s->rate_limit_sem); - urgent =3D true; - } - trace_migration_thread_ratelimit_post(urgent); - } + urgent =3D migration_rate_limit(); } =20 trace_migration_thread_after_loop(); diff --git a/migration/migration.h b/migration/migration.h index 79b3dda146..aa9ff6f27b 100644 --- a/migration/migration.h +++ b/migration/migration.h @@ -341,5 +341,6 @@ int foreach_not_ignored_block(RAMBlockIterFunc func, vo= id *opaque); =20 void migration_make_urgent_request(void); void migration_consume_urgent_request(void); +bool migration_rate_limit(void); =20 #endif diff --git a/migration/ram.c b/migration/ram.c index 825f47f517..aa6cc7d47a 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -2639,6 +2639,8 @@ static int ram_save_host_page(RAMState *rs, PageSearc= hStatus *pss, =20 pages +=3D tmppages; pss->page++; + /* Allow rate limiting to happen in the middle of huge pages */ + migration_rate_limit(); } while ((pss->page & (pagesize_bits - 1)) && offset_in_ramblock(pss->block, pss->page << TARGET_PAGE_BITS)= ); =20 diff --git a/migration/trace-events b/migration/trace-events index 6dee7b5389..2f9129e213 100644 --- a/migration/trace-events +++ b/migration/trace-events @@ -138,12 +138,12 @@ migrate_send_rp_recv_bitmap(char *name, int64_t size)= "block '%s' size 0x%"PRIi6 migration_completion_file_err(void) "" migration_completion_postcopy_end(void) "" migration_completion_postcopy_end_after_complete(void) "" +migration_rate_limit_pre(int ms) "%d ms" +migration_rate_limit_post(int urgent) "urgent: %d" migration_return_path_end_before(void) "" migration_return_path_end_after(int rp_error) "%d" migration_thread_after_loop(void) "" migration_thread_file_err(void) "" -migration_thread_ratelimit_pre(int ms) "%d ms" -migration_thread_ratelimit_post(int urgent) "urgent: %d" migration_thread_setup_complete(void) "" open_return_path_on_source(void) "" open_return_path_on_source_continue(void) "" --=20 2.24.1