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| author | Leonardo Bras | 2022-07-11 23:11:13 +0200 |
|---|---|---|
| committer | Dr. David Alan Gilbert | 2022-07-20 13:15:09 +0200 |
| commit | d59c40cc483729f2e67c80e58df769ad19976fe9 (patch) | |
| tree | 252bf54ccd0ff3a7f405dd8691a98dcbad79e595 /migration | |
| parent | Add dirty-sync-missed-zero-copy migration stat (diff) | |
| download | qemu-d59c40cc483729f2e67c80e58df769ad19976fe9.tar.gz qemu-d59c40cc483729f2e67c80e58df769ad19976fe9.tar.xz qemu-d59c40cc483729f2e67c80e58df769ad19976fe9.zip | |
migration/multifd: Report to user when zerocopy not working
Some errors, like the lack of Scatter-Gather support by the network
interface(NETIF_F_SG) may cause sendmsg(...,MSG_ZEROCOPY) to fail on using
zero-copy, which causes it to fall back to the default copying mechanism.
After each full dirty-bitmap scan there should be a zero-copy flush
happening, which checks for errors each of the previous calls to
sendmsg(...,MSG_ZEROCOPY). If all of them failed to use zero-copy, then
increment dirty_sync_missed_zero_copy migration stat to let the user know
about it.
Signed-off-by: Leonardo Bras <leobras@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Acked-by: Peter Xu <peterx@redhat.com>
Message-Id: <20220711211112.18951-4-leobras@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Diffstat (limited to 'migration')
| -rw-r--r-- | migration/multifd.c | 2 | ||||
| -rw-r--r-- | migration/ram.c | 5 | ||||
| -rw-r--r-- | migration/ram.h | 2 |
3 files changed, 9 insertions, 0 deletions
diff --git a/migration/multifd.c b/migration/multifd.c index 1e49594b02..586ddc9d65 100644 --- a/migration/multifd.c +++ b/migration/multifd.c @@ -624,6 +624,8 @@ int multifd_send_sync_main(QEMUFile *f) if (ret < 0) { error_report_err(err); return -1; + } else if (ret == 1) { + dirty_sync_missed_zero_copy(); } } } diff --git a/migration/ram.c b/migration/ram.c index 4fbad74c6c..b94669ba5d 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -434,6 +434,11 @@ static void ram_transferred_add(uint64_t bytes) ram_counters.transferred += bytes; } +void dirty_sync_missed_zero_copy(void) +{ + ram_counters.dirty_sync_missed_zero_copy++; +} + /* used by the search for pages to send */ struct PageSearchStatus { /* Current block being searched */ diff --git a/migration/ram.h b/migration/ram.h index 5d90945a6e..c7af65ac74 100644 --- a/migration/ram.h +++ b/migration/ram.h @@ -89,4 +89,6 @@ void ram_write_tracking_prepare(void); int ram_write_tracking_start(void); void ram_write_tracking_stop(void); +void dirty_sync_missed_zero_copy(void); + #endif |