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authorPeter Xu <peterx@redhat.com>2018-02-08 18:31:06 +0800
committerDr. David Alan Gilbert <dgilbert@redhat.com>2018-02-14 10:35:45 +0000
commit64f615fe34b4d9e2487fbe61ecb7b4041fc6beb9 (patch)
treec49745f6c1aa5f450a6251fec3f97d1a085c14a1 /migration
parent7a9ddfbfae4aaf8a7e4dafb57ac9fecad807a6b7 (diff)
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migration: reuse mis->userfault_quit_fd
It was only used for quitting the page fault thread before. Let it be something more useful - now we can use it to notify a "wake" for the page fault thread (for any reason), and it only means "quit" if the fault_thread_quit is set. Since we changed what it does, renaming it to userfault_event_fd. Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Signed-off-by: Peter Xu <peterx@redhat.com> Message-Id: <20180208103132.28452-3-peterx@redhat.com> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Diffstat (limited to 'migration')
-rw-r--r--migration/migration.h6
-rw-r--r--migration/postcopy-ram.c29
2 files changed, 24 insertions, 11 deletions
diff --git a/migration/migration.h b/migration/migration.h
index 848f638..75c72d3 100644
--- a/migration/migration.h
+++ b/migration/migration.h
@@ -35,6 +35,8 @@ struct MigrationIncomingState {
bool have_fault_thread;
QemuThread fault_thread;
QemuSemaphore fault_thread_sem;
+ /* Set this when we want the fault thread to quit */
+ bool fault_thread_quit;
bool have_listen_thread;
QemuThread listen_thread;
@@ -42,8 +44,8 @@ struct MigrationIncomingState {
/* For the kernel to send us notifications */
int userfault_fd;
- /* To tell the fault_thread to quit */
- int userfault_quit_fd;
+ /* To notify the fault_thread to wake, e.g., when need to quit */
+ int userfault_event_fd;
QEMUFile *to_src_file;
QemuMutex rp_mutex; /* We send replies from multiple threads */
void *postcopy_tmp_page;
diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
index bec6c2c..9ad4f20 100644
--- a/migration/postcopy-ram.c
+++ b/migration/postcopy-ram.c
@@ -387,17 +387,18 @@ int postcopy_ram_incoming_cleanup(MigrationIncomingState *mis)
* currently be at 0, we're going to increment it to 1
*/
tmp64 = 1;
- if (write(mis->userfault_quit_fd, &tmp64, 8) == 8) {
+ atomic_set(&mis->fault_thread_quit, 1);
+ if (write(mis->userfault_event_fd, &tmp64, 8) == 8) {
trace_postcopy_ram_incoming_cleanup_join();
qemu_thread_join(&mis->fault_thread);
} else {
/* Not much we can do here, but may as well report it */
- error_report("%s: incrementing userfault_quit_fd: %s", __func__,
+ error_report("%s: incrementing userfault_event_fd: %s", __func__,
strerror(errno));
}
trace_postcopy_ram_incoming_cleanup_closeuf();
close(mis->userfault_fd);
- close(mis->userfault_quit_fd);
+ close(mis->userfault_event_fd);
mis->have_fault_thread = false;
}
@@ -520,7 +521,7 @@ static void *postcopy_ram_fault_thread(void *opaque)
pfd[0].fd = mis->userfault_fd;
pfd[0].events = POLLIN;
pfd[0].revents = 0;
- pfd[1].fd = mis->userfault_quit_fd;
+ pfd[1].fd = mis->userfault_event_fd;
pfd[1].events = POLLIN; /* Waiting for eventfd to go positive */
pfd[1].revents = 0;
@@ -530,8 +531,18 @@ static void *postcopy_ram_fault_thread(void *opaque)
}
if (pfd[1].revents) {
- trace_postcopy_ram_fault_thread_quit();
- break;
+ uint64_t tmp64 = 0;
+
+ /* Consume the signal */
+ if (read(mis->userfault_event_fd, &tmp64, 8) != 8) {
+ /* Nothing obviously nicer than posting this error. */
+ error_report("%s: read() failed", __func__);
+ }
+
+ if (atomic_read(&mis->fault_thread_quit)) {
+ trace_postcopy_ram_fault_thread_quit();
+ break;
+ }
}
ret = read(mis->userfault_fd, &msg, sizeof(msg));
@@ -610,9 +621,9 @@ int postcopy_ram_enable_notify(MigrationIncomingState *mis)
}
/* Now an eventfd we use to tell the fault-thread to quit */
- mis->userfault_quit_fd = eventfd(0, EFD_CLOEXEC);
- if (mis->userfault_quit_fd == -1) {
- error_report("%s: Opening userfault_quit_fd: %s", __func__,
+ mis->userfault_event_fd = eventfd(0, EFD_CLOEXEC);
+ if (mis->userfault_event_fd == -1) {
+ error_report("%s: Opening userfault_event_fd: %s", __func__,
strerror(errno));
close(mis->userfault_fd);
return -1;