93fa9dc2e0
It is possible that one of the multifd channels fails to be created at multifd_new_send_channel_async() while the rest of the channel creation tasks are still in flight. This could lead to multifd_save_cleanup() executing the qemu_thread_join() loop too early and not waiting for the threads which haven't been created yet, leading to the freeing of resources that the newly created threads will try to access and crash. Add a synchronization point after which there will be no attempts at thread creation and therefore calling multifd_save_cleanup() past that point will ensure it properly waits for the threads. A note about performance: Prior to this patch, if a channel took too long to be established, other channels could finish connecting first and already start taking load. Now we're bounded by the slowest-connecting channel. Reported-by: Avihai Horon <avihaih@nvidia.com> Reviewed-by: Peter Xu <peterx@redhat.com> Signed-off-by: Fabiano Rosas <farosas@suse.de> Link: https://lore.kernel.org/r/20240206215118.6171-7-farosas@suse.de Signed-off-by: Peter Xu <peterx@redhat.com> |
||
|---|---|---|
| .. | ||
| block-dirty-bitmap.c | ||
| block.c | ||
| block.h | ||
| channel-block.c | ||
| channel-block.h | ||
| channel.c | ||
| channel.h | ||
| colo-failover.c | ||
| colo.c | ||
| dirtyrate.c | ||
| dirtyrate.h | ||
| exec.c | ||
| exec.h | ||
| fd.c | ||
| fd.h | ||
| file.c | ||
| file.h | ||
| global_state.c | ||
| meson.build | ||
| migration-hmp-cmds.c | ||
| migration-stats.c | ||
| migration-stats.h | ||
| migration.c | ||
| migration.h | ||
| multifd-zlib.c | ||
| multifd-zstd.c | ||
| multifd.c | ||
| multifd.h | ||
| options.c | ||
| options.h | ||
| page_cache.c | ||
| page_cache.h | ||
| postcopy-ram.c | ||
| postcopy-ram.h | ||
| qemu-file.c | ||
| qemu-file.h | ||
| ram-compress.c | ||
| ram-compress.h | ||
| ram.c | ||
| ram.h | ||
| rdma.c | ||
| rdma.h | ||
| savevm.c | ||
| savevm.h | ||
| socket.c | ||
| socket.h | ||
| target.c | ||
| threadinfo.c | ||
| threadinfo.h | ||
| tls.c | ||
| tls.h | ||
| trace-events | ||
| trace.h | ||
| vmstate-types.c | ||
| vmstate.c | ||
| xbzrle.c | ||
| xbzrle.h | ||
| yank_functions.c | ||
| yank_functions.h | ||