Re: [PATCH v3 8/8] migration: Tracepoint change in postcopy-run bottom half

[David Edmondson <david.edmondson@oracle.com>]

On Friday, 2021-12-24 at 14:50:00 +08, Peter Xu wrote:

> Remove the old two tracepoints and they're even near each other:
>
>     trace_loadvm_postcopy_handle_run_cpu_sync()
>     trace_loadvm_postcopy_handle_run_vmstart()
>
> Add trace_loadvm_postcopy_handle_run_bh() with a finer granule trace.
>
> Signed-off-by: Peter Xu <peterx@redhat.com>

Reviewed-by: David Edmondson <david.edmondson@oracle.com>

> ---
>  migration/savevm.c     | 12 +++++++++---
>  migration/trace-events |  3 +--
>  2 files changed, 10 insertions(+), 5 deletions(-)
>
> diff --git a/migration/savevm.c b/migration/savevm.c
> index 592d550a2f..3b8f565b14 100644
> --- a/migration/savevm.c
> +++ b/migration/savevm.c
> @@ -2005,13 +2005,19 @@ static void loadvm_postcopy_handle_run_bh(void *opaque)
>      Error *local_err = NULL;
>      MigrationIncomingState *mis = opaque;
>
> +    trace_loadvm_postcopy_handle_run_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");
> +
>      qemu_announce_self(&mis->announce_timer, migrate_announce_params());
>
> +    trace_loadvm_postcopy_handle_run_bh("after announce");
> +
>      /* Make sure all file formats flush their mutable metadata.
>       * If we get an error here, just don't restart the VM yet. */
>      bdrv_invalidate_cache_all(&local_err);
> @@ -2021,9 +2027,7 @@ static void loadvm_postcopy_handle_run_bh(void *opaque)
>          autostart = false;
>      }
>
> -    trace_loadvm_postcopy_handle_run_cpu_sync();
> -
> -    trace_loadvm_postcopy_handle_run_vmstart();
> +    trace_loadvm_postcopy_handle_run_bh("after invalidate cache");
>
>      dirty_bitmap_mig_before_vm_start();
>
> @@ -2036,6 +2040,8 @@ static void loadvm_postcopy_handle_run_bh(void *opaque)
>      }
>
>      qemu_bh_delete(mis->bh);
> +
> +    trace_loadvm_postcopy_handle_run_bh("return");
>  }
>
>  /* After all discards we can start running and asking for pages */
> diff --git a/migration/trace-events b/migration/trace-events
> index 77d1237d89..e165687af2 100644
> --- a/migration/trace-events
> +++ b/migration/trace-events
> @@ -16,8 +16,7 @@ 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_cpu_sync(void) ""
> -loadvm_postcopy_handle_run_vmstart(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) ""

dme.
-- 
Jane was in her turtle neck, I was much happier then.