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authorIvan Ren <ivanren@tencent.com>2019-08-29 10:16:36 +0800
committerDr. David Alan Gilbert <dgilbert@redhat.com>2019-09-12 10:53:33 +0100
commit2f4aefd320a8c3aeb739d59724c5c4dd6a995919 (patch)
tree91c5bc1701cf0abaeb2152dfc59dacdaadb0423d /migration
parent89ea03a7dc83ca36b670ba7f787802791fcb04b1 (diff)
downloadqemu-arm-2f4aefd320a8c3aeb739d59724c5c4dd6a995919.tar.gz
migration: multifd_send_thread always post p->sem_sync when error happen
When encounter error, multifd_send_thread should always notify who pay attention to it before exit. Otherwise it may block migration_thread at multifd_send_sync_main forever. Error as follow: ------------------------------------------------------------------------------- (gdb) bt #0 0x00007f4d669dfa0b in do_futex_wait.constprop.1 () from /lib64/libpthread.so.0 #1 0x00007f4d669dfa9f in __new_sem_wait_slow.constprop.0 () from /lib64/libpthread.so.0 #2 0x00007f4d669dfb3b in sem_wait@@GLIBC_2.2.5 () from /lib64/libpthread.so.0 #3 0x0000562ccf0a5614 in qemu_sem_wait (sem=sem@entry=0x562cd1b698e8) at util/qemu-thread-posix.c:319 #4 0x0000562ccecb4752 in multifd_send_sync_main (rs=<optimized out>) at /qemu/migration/ram.c:1099 #5 0x0000562ccecb95f4 in ram_save_iterate (f=0x562cd0ecc000, opaque=<optimized out>) at /qemu/migration/ram.c:3550 #6 0x0000562ccef43c23 in qemu_savevm_state_iterate (f=0x562cd0ecc000, postcopy=false) at migration/savevm.c:1189 #7 0x0000562ccef3dcf3 in migration_iteration_run (s=0x562cd09fabf0) at migration/migration.c:3131 #8 migration_thread (opaque=opaque@entry=0x562cd09fabf0) at migration/migration.c:3258 #9 0x0000562ccf0a4c26 in qemu_thread_start (args=<optimized out>) at util/qemu-thread-posix.c:502 #10 0x00007f4d669d9e25 in start_thread () from /lib64/libpthread.so.0 #11 0x00007f4d6670635d in clone () from /lib64/libc.so.6 (gdb) f 4 #4 0x0000562ccecb4752 in multifd_send_sync_main (rs=<optimized out>) at /qemu/migration/ram.c:1099 1099 qemu_sem_wait(&p->sem_sync); (gdb) list 1094 } 1095 for (i = 0; i < migrate_multifd_channels(); i++) { 1096 MultiFDSendParams *p = &multifd_send_state->params[i]; 1097 1098 trace_multifd_send_sync_main_wait(p->id); 1099 qemu_sem_wait(&p->sem_sync); 1100 } 1101 trace_multifd_send_sync_main(multifd_send_state->packet_num); 1102 } 1103 (gdb) p i $1 = 0 (gdb) p multifd_send_state->params[0].pending_job $2 = 2 //It means the job before MULTIFD_FLAG_SYNC has already fail (gdb) p multifd_send_state->params[0].quit $3 = true Signed-off-by: Ivan Ren <ivanren@tencent.com> Message-Id: <1567044996-2362-1-git-send-email-ivanren@tencent.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Diffstat (limited to 'migration')
-rw-r--r--migration/ram.c5
1 files changed, 2 insertions, 3 deletions
diff --git a/migration/ram.c b/migration/ram.c
index b01a37e7ca..0047286b7e 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -1112,6 +1112,7 @@ static void *multifd_send_thread(void *opaque)
rcu_register_thread();
if (multifd_send_initial_packet(p, &local_err) < 0) {
+ ret = -1;
goto out;
}
/* initial packet */
@@ -1179,9 +1180,7 @@ out:
* who pay attention to me.
*/
if (ret != 0) {
- if (flags & MULTIFD_FLAG_SYNC) {
- qemu_sem_post(&p->sem_sync);
- }
+ qemu_sem_post(&p->sem_sync);
qemu_sem_post(&multifd_send_state->channels_ready);
}