From nobody Wed Feb 11 06:31:38 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; 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 Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1670087491732329.3367126371353; Sat, 3 Dec 2022 09:11:31 -0800 (PST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1p1W1e-0000bL-Dl; Sat, 03 Dec 2022 12:10:06 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1p1W1d-0000bB-RS for qemu-devel@nongnu.org; Sat, 03 Dec 2022 12:10:05 -0500 Received: from prt-mail.chinatelecom.cn ([42.123.76.219] helo=chinatelecom.cn) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1p1W1b-0006Xn-9j for qemu-devel@nongnu.org; Sat, 03 Dec 2022 12:10:05 -0500 Received: from clientip-125.69.43.82 (unknown [172.18.0.218]) by chinatelecom.cn (HERMES) with SMTP id 1471D2800BA; Sun, 4 Dec 2022 01:09:59 +0800 (CST) Received: from ([125.69.43.82]) by app0025 with ESMTP id 958c0e4bb3fe4f91aedd4b62dc08be54 for qemu-devel@nongnu.org; Sun, 04 Dec 2022 01:10:02 CST HMM_SOURCE_IP: 172.18.0.218:60462.1823367042 HMM_ATTACHE_NUM: 0000 HMM_SOURCE_TYPE: SMTP X-189-SAVE-TO-SEND: +huangy81@chinatelecom.cn X-Transaction-ID: 958c0e4bb3fe4f91aedd4b62dc08be54 X-Real-From: huangy81@chinatelecom.cn X-Receive-IP: 125.69.43.82 X-MEDUSA-Status: 0 From: huangy81@chinatelecom.cn To: qemu-devel Cc: Peter Xu , Markus Armbruster , "Dr. David Alan Gilbert" , Paolo Bonzini , Laurent Vivier , Eric Blake , Juan Quintela , Thomas Huth , Peter Maydell , Richard Henderson , =?UTF-8?q?Hyman=20Huang=28=E9=BB=84=E5=8B=87=29?= Subject: [PATCH RESEND v3 08/10] migration: Implement dirty-limit convergence algo Date: Sun, 4 Dec 2022 01:09:11 +0800 Message-Id: <60408b08bf680b30393c8aa6d1422189521ca8cc.1670087276.git.huangy81@chinatelecom.cn> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: References: In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" 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=42.123.76.219; envelope-from=huangy81@chinatelecom.cn; helo=chinatelecom.cn X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, SPF_HELO_PASS=-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: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZM-MESSAGEID: 1670087493029100004 From: Hyman Huang(=E9=BB=84=E5=8B=87) Implement dirty-limit convergence algo for live migration, which is kind of like auto-converge algo but using dirty-limit instead of cpu throttle to make migration convergent. Enable dirty page limit if dirty_rate_high_cnt greater than 2 when dirty-limit capability enabled, disable dirty-limit if migration be cancled. Note that "set_vcpu_dirty_limit", "cancel_vcpu_dirty_limit" commands are not allowed during dirty-limit live migration. Signed-off-by: Hyman Huang(=E9=BB=84=E5=8B=87) --- migration/migration.c | 3 +++ migration/ram.c | 63 ++++++++++++++++++++++++++++++++++++++--------= ---- migration/trace-events | 1 + softmmu/dirtylimit.c | 22 ++++++++++++++++++ 4 files changed, 74 insertions(+), 15 deletions(-) diff --git a/migration/migration.c b/migration/migration.c index 702e7f4..127d0fe 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -240,6 +240,9 @@ void migration_cancel(const Error *error) if (error) { migrate_set_error(current_migration, error); } + if (migrate_dirty_limit()) { + qmp_cancel_vcpu_dirty_limit(false, -1, NULL); + } migrate_fd_cancel(current_migration); } =20 diff --git a/migration/ram.c b/migration/ram.c index 5e66652..78b9167 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -45,6 +45,7 @@ #include "qapi/error.h" #include "qapi/qapi-types-migration.h" #include "qapi/qapi-events-migration.h" +#include "qapi/qapi-commands-migration.h" #include "qapi/qmp/qerror.h" #include "trace.h" #include "exec/ram_addr.h" @@ -57,6 +58,8 @@ #include "qemu/iov.h" #include "multifd.h" #include "sysemu/runstate.h" +#include "sysemu/dirtylimit.h" +#include "sysemu/kvm.h" =20 #include "hw/boards.h" /* for machine_dump_guest_core() */ =20 @@ -1139,6 +1142,30 @@ static void migration_update_rates(RAMState *rs, int= 64_t end_time) } } =20 +/* + * Enable dirty-limit to throttle down the guest + */ +static void migration_dirty_limit_guest(void) +{ + static int64_t quota_dirtyrate; + MigrationState *s =3D migrate_get_current(); + + /* + * If dirty limit already enabled and migration parameter + * vcpu-dirty-limit untouched. + */ + if (dirtylimit_in_service() && + quota_dirtyrate =3D=3D s->parameters.vcpu_dirty_limit) { + return; + } + + quota_dirtyrate =3D s->parameters.vcpu_dirty_limit; + + /* Set or update quota dirty limit */ + qmp_set_vcpu_dirty_limit(false, -1, quota_dirtyrate, NULL); + trace_migration_dirty_limit_guest(quota_dirtyrate); +} + static void migration_trigger_throttle(RAMState *rs) { MigrationState *s =3D migrate_get_current(); @@ -1148,26 +1175,32 @@ static void migration_trigger_throttle(RAMState *rs) uint64_t bytes_dirty_period =3D rs->num_dirty_pages_period * TARGET_PA= GE_SIZE; uint64_t bytes_dirty_threshold =3D bytes_xfer_period * threshold / 100; =20 - /* During block migration the auto-converge logic incorrectly detects - * that ram migration makes no progress. Avoid this by disabling the - * throttling logic during the bulk phase of block migration. */ - if (blk_mig_bulk_active()) { - return; - } + /* + * The following detection logic can be refined later. For now: + * Check to see if the ratio between dirtied bytes and the approx. + * amount of bytes that just got transferred since the last time + * we were in this routine reaches the threshold. If that happens + * twice, start or increase throttling. + */ =20 - if (migrate_auto_converge()) { - /* The following detection logic can be refined later. For now: - Check to see if the ratio between dirtied bytes and the approx. - amount of bytes that just got transferred since the last time - we were in this routine reaches the threshold. If that happens - twice, start or increase throttling. */ + if ((bytes_dirty_period > bytes_dirty_threshold) && + (++rs->dirty_rate_high_cnt >=3D 2)) { + rs->dirty_rate_high_cnt =3D 0; + /* + * During block migration the auto-converge logic incorrectly dete= cts + * that ram migration makes no progress. Avoid this by disabling t= he + * throttling logic during the bulk phase of block migration + */ + if (blk_mig_bulk_active()) { + return; + } =20 - if ((bytes_dirty_period > bytes_dirty_threshold) && - (++rs->dirty_rate_high_cnt >=3D 2)) { + if (migrate_auto_converge()) { trace_migration_throttle(); - rs->dirty_rate_high_cnt =3D 0; mig_throttle_guest_down(bytes_dirty_period, bytes_dirty_threshold); + } else if (migrate_dirty_limit()) { + migration_dirty_limit_guest(); } } } diff --git a/migration/trace-events b/migration/trace-events index 57003ed..33a2666 100644 --- a/migration/trace-events +++ b/migration/trace-events @@ -91,6 +91,7 @@ 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" migration_throttle(void) "" +migration_dirty_limit_guest(int64_t dirtyrate) "guest dirty page rate limi= t %" PRIi64 " MB/s" ram_discard_range(const char *rbname, uint64_t start, size_t len) "%s: sta= rt: %" PRIx64 " %zx" ram_load_loop(const char *rbname, uint64_t addr, int flags, void *host) "%= s: addr: 0x%" PRIx64 " flags: 0x%x host: %p" ram_load_postcopy_loop(int channel, uint64_t addr, int flags) "chan=3D%d a= ddr=3D0x%" PRIx64 " flags=3D0x%x" diff --git a/softmmu/dirtylimit.c b/softmmu/dirtylimit.c index 2a07200..b63032c 100644 --- a/softmmu/dirtylimit.c +++ b/softmmu/dirtylimit.c @@ -439,6 +439,8 @@ void qmp_cancel_vcpu_dirty_limit(bool has_cpu_index, int64_t cpu_index, Error **errp) { + MigrationState *ms =3D migrate_get_current(); + if (!kvm_enabled() || !kvm_dirty_ring_enabled()) { return; } @@ -452,6 +454,15 @@ void qmp_cancel_vcpu_dirty_limit(bool has_cpu_index, return; } =20 + if (migration_is_running(ms->state) && + (!qemu_thread_is_self(&ms->thread)) && + migrate_dirty_limit() && + dirtylimit_in_service()) { + error_setg(errp, "dirty-limit live migration is running, do" + " not allow dirty page limit to be canceled manually"); + return; + } + dirtylimit_state_lock(); =20 if (has_cpu_index) { @@ -487,6 +498,8 @@ void qmp_set_vcpu_dirty_limit(bool has_cpu_index, uint64_t dirty_rate, Error **errp) { + MigrationState *ms =3D migrate_get_current(); + if (!kvm_enabled() || !kvm_dirty_ring_enabled()) { error_setg(errp, "dirty page limit feature requires KVM with" " accelerator property 'dirty-ring-size' set'"); @@ -503,6 +516,15 @@ void qmp_set_vcpu_dirty_limit(bool has_cpu_index, return; } =20 + if (migration_is_running(ms->state) && + (!qemu_thread_is_self(&ms->thread)) && + migrate_dirty_limit() && + dirtylimit_in_service()) { + error_setg(errp, "dirty-limit live migration is running, do" + " not allow dirty page limit to be configured manually"= ); + return; + } + dirtylimit_state_lock(); =20 if (!dirtylimit_in_service()) { --=20 1.8.3.1