From: Peter Xu <pet...@redhat.com> This patch is inspired by Joao Martin's patch here:
https://lore.kernel.org/r/20230926161841.98464-1-joao.m.mart...@oracle.com Add tracepoints for major downtime checkpoints on both src and dst. They share the same tracepoint with a string showing its stage. Besides the checkpoints in the previous patch, this patch also added destination checkpoints. On src, we have these checkpoints added: - src-downtime-start: right before vm stops on src - src-vm-stopped: after vm is fully stopped - src-iterable-saved: after all iterables saved (END sections) - src-non-iterable-saved: after all non-iterable saved (FULL sections) - src-downtime-stop: migration fully completed On dst, we have these checkpoints added: - dst-precopy-loadvm-completes: after loadvm all done for precopy - dst-precopy-bh-*: record BH steps to resume VM for precopy - dst-postcopy-bh-*: record BH steps to resume VM for postcopy On dst side, we don't have a good way to trace total time consumed by iterable or non-iterable for now. We can mark it by 1st time receiving a FULL / END section, but rather than that let's just rely on the other tracepoints added for vmstates to back up the information. With this patch, one can enable "vmstate_downtime*" tracepoints and it'll enable all tracepoints for downtime measurements necessary. Drop loadvm_postcopy_handle_run_bh() tracepoint alongside, because they service the same purpose, which was only for postcopy. We then have unified prefix for all downtime relevant tracepoints. Co-developed-by: Joao Martins <joao.m.mart...@oracle.com> Signed-off-by: Peter Xu <pet...@redhat.com> Reviewed-by: Juan Quintela <quint...@redhat.com> Signed-off-by: Juan Quintela <quint...@redhat.com> Message-ID: <20231030163346.765724-6-pet...@redhat.com> --- migration/migration.c | 16 +++++++++++++++- migration/savevm.c | 14 +++++++++----- migration/trace-events | 2 +- 3 files changed, 25 insertions(+), 7 deletions(-) diff --git a/migration/migration.c b/migration/migration.c index 3e38294485..c334b9effd 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -103,6 +103,7 @@ static int close_return_path_on_source(MigrationState *s); static void migration_downtime_start(MigrationState *s) { + trace_vmstate_downtime_checkpoint("src-downtime-start"); s->downtime_start = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); } @@ -117,6 +118,8 @@ static void migration_downtime_end(MigrationState *s) if (!s->downtime) { s->downtime = now - s->downtime_start; } + + trace_vmstate_downtime_checkpoint("src-downtime-end"); } static bool migration_needs_multiple_sockets(void) @@ -151,7 +154,11 @@ static gint page_request_addr_cmp(gconstpointer ap, gconstpointer bp) int migration_stop_vm(RunState state) { - return vm_stop_force_state(state); + int ret = vm_stop_force_state(state); + + trace_vmstate_downtime_checkpoint("src-vm-stopped"); + + return ret; } void migration_object_init(void) @@ -495,6 +502,8 @@ static void process_incoming_migration_bh(void *opaque) Error *local_err = NULL; MigrationIncomingState *mis = opaque; + trace_vmstate_downtime_checkpoint("dst-precopy-bh-enter"); + /* If capability late_block_activate is set: * Only fire up the block code now if we're going to restart the * VM, else 'cont' will do it. @@ -520,6 +529,8 @@ static void process_incoming_migration_bh(void *opaque) */ qemu_announce_self(&mis->announce_timer, migrate_announce_params()); + trace_vmstate_downtime_checkpoint("dst-precopy-bh-announced"); + multifd_load_shutdown(); dirty_bitmap_mig_before_vm_start(); @@ -537,6 +548,7 @@ static void process_incoming_migration_bh(void *opaque) } else { runstate_set(global_state_get_runstate()); } + trace_vmstate_downtime_checkpoint("dst-precopy-bh-vm-started"); /* * This must happen after any state changes since as soon as an external * observer sees this event they might start to prod at the VM assuming @@ -571,6 +583,8 @@ process_incoming_migration_co(void *opaque) ret = qemu_loadvm_state(mis->from_src_file); mis->loadvm_co = NULL; + trace_vmstate_downtime_checkpoint("dst-precopy-loadvm-completed"); + ps = postcopy_state_get(); trace_process_incoming_migration_co_end(ret, ps); if (ps != POSTCOPY_INCOMING_NONE) { diff --git a/migration/savevm.c b/migration/savevm.c index 99ce42b6f3..bc98c2ea6f 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -1526,6 +1526,8 @@ int qemu_savevm_state_complete_precopy_iterable(QEMUFile *f, bool in_postcopy) end_ts_each - start_ts_each); } + trace_vmstate_downtime_checkpoint("src-iterable-saved"); + return 0; } @@ -1592,6 +1594,8 @@ int qemu_savevm_state_complete_precopy_non_iterable(QEMUFile *f, json_writer_free(vmdesc); ms->vmdesc = NULL; + trace_vmstate_downtime_checkpoint("src-non-iterable-saved"); + return 0; } @@ -2133,18 +2137,18 @@ static void loadvm_postcopy_handle_run_bh(void *opaque) Error *local_err = NULL; MigrationIncomingState *mis = opaque; - trace_loadvm_postcopy_handle_run_bh("enter"); + trace_vmstate_downtime_checkpoint("dst-postcopy-bh-enter"); /* TODO we should move all of this lot into postcopy_ram.c or a shared code * in migration.c */ cpu_synchronize_all_post_init(); - trace_loadvm_postcopy_handle_run_bh("after cpu sync"); + trace_vmstate_downtime_checkpoint("dst-postcopy-bh-cpu-synced"); qemu_announce_self(&mis->announce_timer, migrate_announce_params()); - trace_loadvm_postcopy_handle_run_bh("after announce"); + trace_vmstate_downtime_checkpoint("dst-postcopy-bh-announced"); /* Make sure all file formats throw away their mutable metadata. * If we get an error here, just don't restart the VM yet. */ @@ -2155,7 +2159,7 @@ static void loadvm_postcopy_handle_run_bh(void *opaque) autostart = false; } - trace_loadvm_postcopy_handle_run_bh("after invalidate cache"); + trace_vmstate_downtime_checkpoint("dst-postcopy-bh-cache-invalidated"); dirty_bitmap_mig_before_vm_start(); @@ -2169,7 +2173,7 @@ static void loadvm_postcopy_handle_run_bh(void *opaque) qemu_bh_delete(mis->bh); - trace_loadvm_postcopy_handle_run_bh("return"); + trace_vmstate_downtime_checkpoint("dst-postcopy-bh-vm-started"); } /* After all discards we can start running and asking for pages */ diff --git a/migration/trace-events b/migration/trace-events index 5820add1f3..e54f317e3b 100644 --- a/migration/trace-events +++ b/migration/trace-events @@ -17,7 +17,6 @@ loadvm_handle_recv_bitmap(char *s) "%s" loadvm_postcopy_handle_advise(void) "" loadvm_postcopy_handle_listen(const char *str) "%s" loadvm_postcopy_handle_run(void) "" -loadvm_postcopy_handle_run_bh(const char *str) "%s" loadvm_postcopy_handle_resume(void) "" loadvm_postcopy_ram_handle_discard(void) "" loadvm_postcopy_ram_handle_discard_end(void) "" @@ -50,6 +49,7 @@ vmstate_save(const char *idstr, const char *vmsd_name) "%s, %s" vmstate_load(const char *idstr, const char *vmsd_name) "%s, %s" vmstate_downtime_save(const char *type, const char *idstr, uint32_t instance_id, int64_t downtime) "type=%s idstr=%s instance_id=%d downtime=%"PRIi64 vmstate_downtime_load(const char *type, const char *idstr, uint32_t instance_id, int64_t downtime) "type=%s idstr=%s instance_id=%d downtime=%"PRIi64 +vmstate_downtime_checkpoint(const char *checkpoint) "%s" postcopy_pause_incoming(void) "" postcopy_pause_incoming_continued(void) "" postcopy_page_req_sync(void *host_addr) "sync page req %p" -- 2.41.0
