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author | Peter Xu <peterx@redhat.com> | 2023-10-30 12:33:44 -0400 |
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committer | Juan Quintela <quintela@redhat.com> | 2023-11-01 16:13:58 +0100 |
commit | 3c80f14272057f77c87fb9971e8c4f603a03289a (patch) | |
tree | 8be7206d4739153ebdcc61d91f20511c2afd1192 /migration/trace-events | |
parent | e22ffad03a32d3fc4717561f8af5ef7d9657728d (diff) | |
download | qemu-3c80f14272057f77c87fb9971e8c4f603a03289a.zip qemu-3c80f14272057f77c87fb9971e8c4f603a03289a.tar.gz qemu-3c80f14272057f77c87fb9971e8c4f603a03289a.tar.bz2 |
migration: Add per vmstate downtime tracepoints
We have a bunch of savevm_section* tracepoints, they're good to analyze
migration stream, but not always suitable if someone would like to analyze
the migration downtime. Two major problems:
- savevm_section* tracepoints are dumping all sections, we only care
about the sections that contribute to the downtime
- They don't have an identifier to show the type of sections, so no way
to filter downtime information either easily.
We can add type into the tracepoints, but instead of doing so, this patch
kept them untouched, instead of adding a bunch of downtime specific
tracepoints, so one can enable "vmstate_downtime*" tracepoints and get a
full picture of how the downtime is distributed across iterative and
non-iterative vmstate save/load.
Note that here both save() and load() need to be traced, because both of
them may contribute to the downtime. The contribution is not a simple "add
them together", though: consider when the src is doing a save() of device1
while the dest can be load()ing for device2, so they can happen
concurrently.
Tracking both sides make sense because device load() and save() can be
imbalanced, one device can save() super fast, but load() super slow, vice
versa. We can't figure that out without tracing both.
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <20231030163346.765724-4-peterx@redhat.com>
Diffstat (limited to 'migration/trace-events')
-rw-r--r-- | migration/trace-events | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/migration/trace-events b/migration/trace-events index fa9486d..5820add 100644 --- a/migration/trace-events +++ b/migration/trace-events @@ -48,6 +48,8 @@ savevm_state_cleanup(void) "" savevm_state_complete_precopy(void) "" 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 postcopy_pause_incoming(void) "" postcopy_pause_incoming_continued(void) "" postcopy_page_req_sync(void *host_addr) "sync page req %p" |