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[Qemu-devel] [RFC 08/29] migration: reuse mis->userfault_quit_fd
From: |
Peter Xu |
Subject: |
[Qemu-devel] [RFC 08/29] migration: reuse mis->userfault_quit_fd |
Date: |
Fri, 28 Jul 2017 16:06:17 +0800 |
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.
Signed-off-by: Peter Xu <address@hidden>
---
migration/migration.h | 6 ++++--
migration/postcopy-ram.c | 24 ++++++++++++++++--------
2 files changed, 20 insertions(+), 10 deletions(-)
diff --git a/migration/migration.h b/migration/migration.h
index 148c9fa..70e3094 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 952b73a..4278fe7 100644
--- a/migration/postcopy-ram.c
+++ b/migration/postcopy-ram.c
@@ -305,7 +305,8 @@ 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 {
@@ -315,7 +316,7 @@ int postcopy_ram_incoming_cleanup(MigrationIncomingState
*mis)
}
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;
}
@@ -438,7 +439,7 @@ 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;
@@ -448,8 +449,15 @@ 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 */
+ read(mis->userfault_event_fd, &tmp64, 8);
+
+ if (atomic_read(&mis->fault_thread_quit)) {
+ trace_postcopy_ram_fault_thread_quit();
+ break;
+ }
}
ret = read(mis->userfault_fd, &msg, sizeof(msg));
@@ -528,9 +536,9 @@ 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;
--
2.7.4
- [Qemu-devel] [RFC 03/29] io: fix qio_channel_socket_accept err handling, (continued)
- [Qemu-devel] [RFC 03/29] io: fix qio_channel_socket_accept err handling, Peter Xu, 2017/07/28
- [Qemu-devel] [RFC 04/29] bitmap: introduce bitmap_invert(), Peter Xu, 2017/07/28
- [Qemu-devel] [RFC 05/29] bitmap: introduce bitmap_count_one(), Peter Xu, 2017/07/28
- [Qemu-devel] [RFC 06/29] migration: dump str in migrate_set_state trace, Peter Xu, 2017/07/28
- [Qemu-devel] [RFC 08/29] migration: reuse mis->userfault_quit_fd,
Peter Xu <=
- [Qemu-devel] [RFC 07/29] migration: better error handling with QEMUFile, Peter Xu, 2017/07/28
- [Qemu-devel] [RFC 09/29] migration: provide postcopy_fault_thread_notify(), Peter Xu, 2017/07/28
- [Qemu-devel] [RFC 10/29] migration: new property "x-postcopy-fast", Peter Xu, 2017/07/28
- [Qemu-devel] [RFC 11/29] migration: new postcopy-pause state, Peter Xu, 2017/07/28