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[Qemu-devel] [PATCH v13 10/12] migration: Wait for blocking IO
From: |
Juan Quintela |
Subject: |
[Qemu-devel] [PATCH v13 10/12] migration: Wait for blocking IO |
Date: |
Wed, 23 May 2018 13:18:15 +0200 |
We have three conditions here:
- channel fails -> error
- we have to quit: we close the channel and reads fails
- normal read that success, we are in bussiness
So forget the complications of waiting in a semaphore.
Signed-off-by: Juan Quintela <address@hidden>
---
migration/ram.c | 81 ++++++++++++++++++-------------------------------
1 file changed, 29 insertions(+), 52 deletions(-)
diff --git a/migration/ram.c b/migration/ram.c
index 2584130c85..a707d3ae80 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -595,8 +595,6 @@ typedef struct {
bool running;
/* should this thread finish */
bool quit;
- /* thread has work to do */
- bool pending_job;
/* array of pages to receive */
MultiFDPages_t *pages;
/* packet allocated len */
@@ -1170,14 +1168,6 @@ static void multifd_recv_sync_main(void)
for (i = 0; i < migrate_multifd_channels(); i++) {
MultiFDRecvParams *p = &multifd_recv_state->params[i];
- trace_multifd_recv_sync_main_signal(p->id);
- qemu_mutex_lock(&p->mutex);
- p->pending_job = true;
- qemu_mutex_unlock(&p->mutex);
- }
- for (i = 0; i < migrate_multifd_channels(); i++) {
- MultiFDRecvParams *p = &multifd_recv_state->params[i];
-
trace_multifd_recv_sync_main_wait(p->id);
qemu_sem_wait(&multifd_recv_state->sem_sync);
qemu_mutex_lock(&p->mutex);
@@ -1190,7 +1180,6 @@ static void multifd_recv_sync_main(void)
MultiFDRecvParams *p = &multifd_recv_state->params[i];
trace_multifd_recv_sync_main_signal(p->id);
-
qemu_sem_post(&p->sem_sync);
}
trace_multifd_recv_sync_main(multifd_recv_state->seq);
@@ -1205,51 +1194,40 @@ static void *multifd_recv_thread(void *opaque)
trace_multifd_recv_thread_start(p->id);
while (true) {
+ uint32_t used;
+ uint32_t flags;
+
+ ret = qio_channel_read_all_eof(p->c, (void *)p->packet,
+ p->packet_len, &local_err);
+ if (ret == 0) { /* EOF */
+ break;
+ }
+ if (ret == -1) { /* Error */
+ break;
+ }
+
qemu_mutex_lock(&p->mutex);
- if (true || p->pending_job) {
- uint32_t used;
- uint32_t flags;
- qemu_mutex_unlock(&p->mutex);
-
- ret = qio_channel_read_all_eof(p->c, (void *)p->packet,
- p->packet_len, &local_err);
- if (ret == 0) { /* EOF */
- break;
- }
- if (ret == -1) { /* Error */
- break;
- }
-
- qemu_mutex_lock(&p->mutex);
- ret = multifd_recv_unfill_packet(p, &local_err);
- if (ret) {
- qemu_mutex_unlock(&p->mutex);
- break;
- }
-
- used = p->pages->used;
- flags = p->flags;
- trace_multifd_recv(p->id, p->seq, used, flags);
- p->pending_job = false;
- p->num_packets++;
- p->num_pages += used;
+ ret = multifd_recv_unfill_packet(p, &local_err);
+ if (ret) {
qemu_mutex_unlock(&p->mutex);
+ break;
+ }
- ret = qio_channel_readv_all(p->c, p->pages->iov, used, &local_err);
- if (ret != 0) {
- break;
- }
+ used = p->pages->used;
+ flags = p->flags;
+ trace_multifd_recv(p->id, p->seq, used, flags);
+ p->num_packets++;
+ p->num_pages += used;
+ qemu_mutex_unlock(&p->mutex);
- if (flags & MULTIFD_FLAG_SYNC) {
- qemu_sem_post(&multifd_recv_state->sem_sync);
- qemu_sem_wait(&p->sem_sync);
- }
- } else if (p->quit) {
- qemu_mutex_unlock(&p->mutex);
+ ret = qio_channel_readv_all(p->c, p->pages->iov, used, &local_err);
+ if (ret != 0) {
break;
- } else {
- qemu_mutex_unlock(&p->mutex);
- /* sometimes there are spurious wakeups */
+ }
+
+ if (flags & MULTIFD_FLAG_SYNC) {
+ qemu_sem_post(&multifd_recv_state->sem_sync);
+ qemu_sem_wait(&p->sem_sync);
}
}
@@ -1287,7 +1265,6 @@ int multifd_load_setup(void)
qemu_sem_init(&p->sem, 0);
qemu_sem_init(&p->sem_sync, 0);
p->quit = false;
- p->pending_job = false;
p->id = i;
p->pages = multifd_pages_init(page_count);
p->packet_len = sizeof(MultiFDPacket_t)
--
2.17.0
- [Qemu-devel] [PATCH v13 01/12] migration: Create multipage support, (continued)
- [Qemu-devel] [PATCH v13 01/12] migration: Create multipage support, Juan Quintela, 2018/05/23
- [Qemu-devel] [PATCH v13 03/12] migration: Add multifd traces for start/end thread, Juan Quintela, 2018/05/23
- [Qemu-devel] [PATCH v13 04/12] migration: Calculate transferred ram correctly, Juan Quintela, 2018/05/23
- [Qemu-devel] [PATCH v13 05/12] migration: Multifd channels always wait on the sem, Juan Quintela, 2018/05/23
- [Qemu-devel] [PATCH v13 02/12] migration: Create multifd packet, Juan Quintela, 2018/05/23
- [Qemu-devel] [PATCH v13 06/12] migration: Add block where to send/receive packets, Juan Quintela, 2018/05/23
- [Qemu-devel] [PATCH v13 08/12] migration: Create ram_save_multifd_page, Juan Quintela, 2018/05/23
- [Qemu-devel] [PATCH v13 07/12] migration: Synchronize multifd threads with main thread, Juan Quintela, 2018/05/23
- [Qemu-devel] [PATCH v13 11/12] migration: Remove not needed semaphore and quit, Juan Quintela, 2018/05/23
- [Qemu-devel] [PATCH v13 09/12] migration: Start sending messages, Juan Quintela, 2018/05/23
- [Qemu-devel] [PATCH v13 10/12] migration: Wait for blocking IO,
Juan Quintela <=
- [Qemu-devel] [PATCH v13 12/12] migration: Stop sending whole pages through main channel, Juan Quintela, 2018/05/23
- Re: [Qemu-devel] [PATCH v13 00/12] Multifd, no-reply, 2018/05/23