motorhead/qemu
1
0
Fork 0
mirror of https://github.com/Motorhead1991/qemu.git synced 2025-08-03 15:53:54 -06:00
Code Issues Projects Releases Packages Wiki Activity Actions

migration: Add postcopy_thread_create()

Browse source 
Postcopy create threads. A common manner is we init a sem and use it to sync
with the thread.  Namely, we have fault_thread_sem and listen_thread_sem and
they're only used for this.

Make it a shared infrastructure so it's easier to create yet another thread.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20220301083925.33483-7-peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
This commit is contained in:
Peter Xu 2022-03-01 16:39:06 +08:00 • committed by Dr. David Alan Gilbert
parent cfc7dc8abf
commit 095c12a4a2
4 changed files with 29 additions and 18 deletions
Download patch file Download diff file Expand all files Collapse all files

23
migration/postcopy-ram.c
View file

@ -78,6 +78,20 @@ int postcopy_notify(enum PostcopyNotifyReason reason, Error **errp)
&pnd);
}
/*
* NOTE: this routine is not thread safe, we can't call it concurrently. But it
* should be good enough for migration's purposes.
*/
void postcopy_thread_create(MigrationIncomingState *mis,
QemuThread *thread, const char *name,
void *(*fn)(void *), int joinable)
{
qemu_sem_init(&mis->thread_sync_sem, 0);
qemu_thread_create(thread, name, fn, mis, joinable);
qemu_sem_wait(&mis->thread_sync_sem);
qemu_sem_destroy(&mis->thread_sync_sem);
}
/* Postcopy needs to detect accesses to pages that haven't yet been copied
* across, and efficiently map new pages in, the techniques for doing this
* are target OS specific.
@ -902,7 +916,7 @@ static void *postcopy_ram_fault_thread(void *opaque)
trace_postcopy_ram_fault_thread_entry();
rcu_register_thread();
mis->last_rb = NULL; /* last RAMBlock we sent part of */
qemu_sem_post(&mis->fault_thread_sem);
qemu_sem_post(&mis->thread_sync_sem);
struct pollfd *pfd;
size_t pfd_len = 2 + mis->postcopy_remote_fds->len;
@ -1173,11 +1187,8 @@ int postcopy_ram_incoming_setup(MigrationIncomingState *mis)
return -1;
}
qemu_sem_init(&mis->fault_thread_sem, 0);
qemu_thread_create(&mis->fault_thread, "postcopy/fault",
postcopy_ram_fault_thread, mis, QEMU_THREAD_JOINABLE);
qemu_sem_wait(&mis->fault_thread_sem);
qemu_sem_destroy(&mis->fault_thread_sem);
postcopy_thread_create(mis, &mis->fault_thread, "postcopy/fault",
postcopy_ram_fault_thread, QEMU_THREAD_JOINABLE);
mis->have_fault_thread = true;
/* Mark so that we get notified of accesses to unwritten areas */