On Wed, Jun 10, 2015 at 10:27:11 -0400, John Ferlan wrote:
On 06/10/2015 09:42 AM, Jiri Denemark wrote:
QEMU will soon (patches are available on qemu-devel) get support for migration events which will finally allow us to get rid of polling query-migrate every 50ms. However, we first need to be able to wait for all events related to migration (migration status changes, block job events, async abort requests) at once. This series prepares the infrastructure and uses it to switch all polling loops in migration code to pthread_cond_wait.
https://bugzilla.redhat.com/show_bug.cgi?id=1212077
Version 3 (see individual patches for details): - most of the series has been ACKed in v2 - "qemu: Use domain condition for synchronous block jobs" was split in 3 patches for easier review - minor changes requested in v2 review
Version 2 (see individual patches for details): - rewritten using per-domain condition variable - enahnced to fully support the migration events
Just ran this through my Coverity checker - only one issue
RESOURCE_LEAK in qemuMigrationRun:
4235 if (qemuMigrationCheckJobStatus(driver, vm, 4236 QEMU_ASYNC_JOB_MIGRATION_OUT) < 0)
(4) Event if_end: End of if statement
4237 goto cancel; 4238
(5) Event open_fn: Returning handle opened by "accept". (6) Event var_assign: Assigning: "fd" = handle returned from "accept(spec->dest.unix_socket.sock, __SOCKADDR_ARG({ .__sockaddr__ = NULL}), NULL)". (7) Event cond_false: Condition "(fd = accept(spec->dest.unix_socket.sock, __SOCKADDR_ARG({ .__sockaddr__ = NULL}), NULL)) < 0", taking false branch Also see events: [leaked_handle]
4239 while ((fd = accept(spec->dest.unix_socket.sock, NULL, NULL)) < 0) { 4240 if (errno == EAGAIN || errno == EINTR) 4241 continue;
Hmm, what an old and unused (except for some ancient QEMU versions) code path :-) However, this code is only executed if spec->destType == MIGRATION_DEST_UNIX, which only happens in tunnelled migration path, which also sets spec.fwdType = MIGRATION_FWD_STREAM. ...
(28) Event cond_false: Condition "spec->fwdType != MIGRATION_FWD_DIRECT", taking false branch
4289 if (spec->fwdType != MIGRATION_FWD_DIRECT) { 4290 if (iothread && qemuMigrationStopTunnel(iothread, ret < 0) < 0) 4291 ret = -1; 4292 VIR_FORCE_CLOSE(fd);
Which means "spec->fwdType != MIGRATION_FWD_DIRECT" will be true and fd will be correctly closed. Jirka