From nobody Tue Oct 28 12:16:32 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1514973144263139.76098219304788; Wed, 3 Jan 2018 01:52:24 -0800 (PST) Received: from localhost ([::1]:46756 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eWfih-000224-Az for importer@patchew.org; Wed, 03 Jan 2018 04:52:23 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34711) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eWfVn-0007IS-T4 for qemu-devel@nongnu.org; Wed, 03 Jan 2018 04:39:05 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eWfVk-0007Bq-NF for qemu-devel@nongnu.org; Wed, 03 Jan 2018 04:39:03 -0500 Received: from mx1.redhat.com ([209.132.183.28]:44100) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eWfVk-0007B7-E5 for qemu-devel@nongnu.org; Wed, 03 Jan 2018 04:39:00 -0500 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 9BF4A80F9C; Wed, 3 Jan 2018 09:38:59 +0000 (UTC) Received: from secure.mitica (ovpn-116-63.ams2.redhat.com [10.36.116.63]) by smtp.corp.redhat.com (Postfix) with ESMTP id EEBF561783; Wed, 3 Jan 2018 09:38:54 +0000 (UTC) From: Juan Quintela To: qemu-devel@nongnu.org Date: Wed, 3 Jan 2018 10:38:29 +0100 Message-Id: <20180103093834.20879-10-quintela@redhat.com> In-Reply-To: <20180103093834.20879-1-quintela@redhat.com> References: <20180103093834.20879-1-quintela@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Wed, 03 Jan 2018 09:38:59 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL 09/14] migration: calculate vCPU blocktime on dst side X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: lvivier@redhat.com, dgilbert@redhat.com, peterx@redhat.com, Alexey Perevalov Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: Alexey Perevalov This patch provides blocktime calculation per vCPU, as a summary and as a overlapped value for all vCPUs. This approach was suggested by Peter Xu, as an improvements of previous approch where QEMU kept tree with faulted page address and cpus bi= tmask in it. Now QEMU is keeping array with faulted page address as value and vCPU as index. It helps to find proper vCPU at UFFD_COPY time. Also it keeps list for blocktime per vCPU (could be traced with page_fault_addr) Blocktime will not calculated if postcopy_blocktime field of MigrationIncomingState wasn't initialized. Signed-off-by: Alexey Perevalov Reviewed-by: Dr. David Alan Gilbert Reviewed-by: Juan Quintela Signed-off-by: Juan Quintela --- migration/postcopy-ram.c | 143 +++++++++++++++++++++++++++++++++++++++++++= +++- migration/trace-events | 5 +- 2 files changed, 146 insertions(+), 2 deletions(-) diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c index c18ec5aa18..6bf24e9596 100644 --- a/migration/postcopy-ram.c +++ b/migration/postcopy-ram.c @@ -553,6 +553,142 @@ static int ram_block_enable_notify(const char *block_= name, void *host_addr, return 0; } =20 +static int get_mem_fault_cpu_index(uint32_t pid) +{ + CPUState *cpu_iter; + + CPU_FOREACH(cpu_iter) { + if (cpu_iter->thread_id =3D=3D pid) { + trace_get_mem_fault_cpu_index(cpu_iter->cpu_index, pid); + return cpu_iter->cpu_index; + } + } + trace_get_mem_fault_cpu_index(-1, pid); + return -1; +} + +/* + * This function is being called when pagefault occurs. It + * tracks down vCPU blocking time. + * + * @addr: faulted host virtual address + * @ptid: faulted process thread id + * @rb: ramblock appropriate to addr + */ +static void mark_postcopy_blocktime_begin(uint64_t addr, uint32_t ptid, + RAMBlock *rb) +{ + int cpu, already_received; + MigrationIncomingState *mis =3D migration_incoming_get_current(); + PostcopyBlocktimeContext *dc =3D mis->blocktime_ctx; + int64_t now_ms; + + if (!dc || ptid =3D=3D 0) { + return; + } + cpu =3D get_mem_fault_cpu_index(ptid); + if (cpu < 0) { + return; + } + + now_ms =3D qemu_clock_get_ms(QEMU_CLOCK_REALTIME); + if (dc->vcpu_addr[cpu] =3D=3D 0) { + atomic_inc(&dc->smp_cpus_down); + } + + atomic_xchg__nocheck(&dc->last_begin, now_ms); + atomic_xchg__nocheck(&dc->page_fault_vcpu_time[cpu], now_ms); + atomic_xchg__nocheck(&dc->vcpu_addr[cpu], addr); + + /* check it here, not at the begining of the function, + * due to, check could accur early than bitmap_set in + * qemu_ufd_copy_ioctl */ + already_received =3D ramblock_recv_bitmap_test(rb, (void *)addr); + if (already_received) { + atomic_xchg__nocheck(&dc->vcpu_addr[cpu], 0); + atomic_xchg__nocheck(&dc->page_fault_vcpu_time[cpu], 0); + atomic_dec(&dc->smp_cpus_down); + } + trace_mark_postcopy_blocktime_begin(addr, dc, dc->page_fault_vcpu_time= [cpu], + cpu, already_received); +} + +/* + * This function just provide calculated blocktime per cpu and trace it. + * Total blocktime is calculated in mark_postcopy_blocktime_end. + * + * + * Assume we have 3 CPU + * + * S1 E1 S1 E1 + * -----***********------------xxx***************------------------------>= CPU1 + * + * S2 E2 + * ------------****************xxx--------------------------------------->= CPU2 + * + * S3 E3 + * ------------------------****xxx********------------------------------->= CPU3 + * + * We have sequence S1,S2,E1,S3,S1,E2,E3,E1 + * S2,E1 - doesn't match condition due to sequence S1,S2,E1 doesn't includ= e CPU3 + * S3,S1,E2 - sequence includes all CPUs, in this case overlap will be S1,= E2 - + * it's a part of total blocktime. + * S1 - here is last_begin + * Legend of the picture is following: + * * - means blocktime per vCPU + * x - means overlapped blocktime (total blocktime) + * + * @addr: host virtual address + */ +static void mark_postcopy_blocktime_end(uint64_t addr) +{ + MigrationIncomingState *mis =3D migration_incoming_get_current(); + PostcopyBlocktimeContext *dc =3D mis->blocktime_ctx; + int i, affected_cpu =3D 0; + int64_t now_ms; + bool vcpu_total_blocktime =3D false; + int64_t read_vcpu_time; + + if (!dc) { + return; + } + + now_ms =3D qemu_clock_get_ms(QEMU_CLOCK_REALTIME); + + /* lookup cpu, to clear it, + * that algorithm looks straighforward, but it's not + * optimal, more optimal algorithm is keeping tree or hash + * where key is address value is a list of */ + for (i =3D 0; i < smp_cpus; i++) { + uint64_t vcpu_blocktime =3D 0; + + read_vcpu_time =3D atomic_fetch_add(&dc->page_fault_vcpu_time[i], = 0); + if (atomic_fetch_add(&dc->vcpu_addr[i], 0) !=3D addr || + read_vcpu_time =3D=3D 0) { + continue; + } + atomic_xchg__nocheck(&dc->vcpu_addr[i], 0); + vcpu_blocktime =3D now_ms - read_vcpu_time; + affected_cpu +=3D 1; + /* we need to know is that mark_postcopy_end was due to + * faulted page, another possible case it's prefetched + * page and in that case we shouldn't be here */ + if (!vcpu_total_blocktime && + atomic_fetch_add(&dc->smp_cpus_down, 0) =3D=3D smp_cpus) { + vcpu_total_blocktime =3D true; + } + /* continue cycle, due to one page could affect several vCPUs */ + dc->vcpu_blocktime[i] +=3D vcpu_blocktime; + } + + atomic_sub(&dc->smp_cpus_down, affected_cpu); + if (vcpu_total_blocktime) { + dc->total_blocktime +=3D now_ms - atomic_fetch_add(&dc->last_begin= , 0); + } + trace_mark_postcopy_blocktime_end(addr, dc, dc->total_blocktime, + affected_cpu); +} + /* * Handle faults detected by the USERFAULT markings */ @@ -630,8 +766,11 @@ static void *postcopy_ram_fault_thread(void *opaque) rb_offset &=3D ~(qemu_ram_pagesize(rb) - 1); trace_postcopy_ram_fault_thread_request(msg.arg.pagefault.address, qemu_ram_get_idstr(rb), - rb_offset); + rb_offset, + msg.arg.pagefault.feat.pti= d); =20 + mark_postcopy_blocktime_begin((uintptr_t)(msg.arg.pagefault.addres= s), + msg.arg.pagefault.feat.ptid, rb); /* * Send the request to the source - we want to request one * of our host page sizes (which is >=3D TPS) @@ -721,6 +860,8 @@ static int qemu_ufd_copy_ioctl(int userfault_fd, void *= host_addr, if (!ret) { ramblock_recv_bitmap_set_range(rb, host_addr, pagesize / qemu_target_page_size()); + mark_postcopy_blocktime_end((uint64_t)(uintptr_t)host_addr); + } return ret; } diff --git a/migration/trace-events b/migration/trace-events index 6f29fcc686..462d15717d 100644 --- a/migration/trace-events +++ b/migration/trace-events @@ -115,6 +115,8 @@ process_incoming_migration_co_end(int ret, int ps) "ret= =3D%d postcopy-state=3D%d" process_incoming_migration_co_postcopy_end_main(void) "" migration_set_incoming_channel(void *ioc, const char *ioctype) "ioc=3D%p i= octype=3D%s" migration_set_outgoing_channel(void *ioc, const char *ioctype, const char = *hostname) "ioc=3D%p ioctype=3D%s hostname=3D%s" +mark_postcopy_blocktime_begin(uint64_t addr, void *dd, int64_t time, int c= pu, int received) "addr: 0x%" PRIx64 ", dd: %p, time: %" PRId64 ", cpu: %d,= already_received: %d" +mark_postcopy_blocktime_end(uint64_t addr, void *dd, int64_t time, int aff= ected_cpu) "addr: 0x%" PRIx64 ", dd: %p, time: %" PRId64 ", affected_cpu: %= d" =20 # migration/rdma.c qemu_rdma_accept_incoming_migration(void) "" @@ -191,7 +193,7 @@ postcopy_ram_enable_notify(void) "" postcopy_ram_fault_thread_entry(void) "" postcopy_ram_fault_thread_exit(void) "" postcopy_ram_fault_thread_quit(void) "" -postcopy_ram_fault_thread_request(uint64_t hostaddr, const char *ramblock,= size_t offset) "Request for HVA=3D0x%" PRIx64 " rb=3D%s offset=3D0x%zx" +postcopy_ram_fault_thread_request(uint64_t hostaddr, const char *ramblock,= size_t offset, uint32_t pid) "Request for HVA=3D0x%" PRIx64 " rb=3D%s offs= et=3D0x%zx pid=3D%u" postcopy_ram_incoming_cleanup_closeuf(void) "" postcopy_ram_incoming_cleanup_entry(void) "" postcopy_ram_incoming_cleanup_exit(void) "" @@ -200,6 +202,7 @@ save_xbzrle_page_skipping(void) "" save_xbzrle_page_overflow(void) "" ram_save_iterate_big_wait(uint64_t milliconds, int iterations) "big wait: = %" PRIu64 " milliseconds, %d iterations" ram_load_complete(int ret, uint64_t seq_iter) "exit_code %d seq iteration = %" PRIu64 +get_mem_fault_cpu_index(int cpu, uint32_t pid) "cpu: %d, pid: %u" =20 # migration/exec.c migration_exec_outgoing(const char *cmd) "cmd=3D%s" --=20 2.14.3