[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH v5 11/17] migration: Really use multiple pages a
From: |
Dr. David Alan Gilbert |
Subject: |
Re: [Qemu-devel] [PATCH v5 11/17] migration: Really use multiple pages at a time |
Date: |
Thu, 20 Jul 2017 10:44:04 +0100 |
User-agent: |
Mutt/1.8.3 (2017-05-23) |
* Juan Quintela (address@hidden) wrote:
> We now send several pages at a time each time that we wakeup a thread.
>
> Signed-off-by: Juan Quintela <address@hidden>
>
> --
>
> Use iovec's insead of creating the equivalent.
> ---
> migration/ram.c | 46 ++++++++++++++++++++++++++++++++++++++++------
> 1 file changed, 40 insertions(+), 6 deletions(-)
>
> diff --git a/migration/ram.c b/migration/ram.c
> index 2bf3fa7..90e1bcb 100644
> --- a/migration/ram.c
> +++ b/migration/ram.c
> @@ -362,6 +362,13 @@ static void compress_threads_save_setup(void)
>
> /* Multiple fd's */
>
> +
> +typedef struct {
> + int num;
> + int size;
size_t ?
> + struct iovec *iov;
> +} multifd_pages_t;
> +
> struct MultiFDSendParams {
> /* not changed */
> uint8_t id;
> @@ -371,7 +378,7 @@ struct MultiFDSendParams {
> QemuMutex mutex;
> /* protected by param mutex */
> bool quit;
> - uint8_t *address;
> + multifd_pages_t pages;
> /* protected by multifd mutex */
> bool done;
> };
> @@ -459,8 +466,8 @@ static void *multifd_send_thread(void *opaque)
> qemu_mutex_unlock(&p->mutex);
> break;
> }
> - if (p->address) {
> - p->address = 0;
> + if (p->pages.num) {
> + p->pages.num = 0;
> qemu_mutex_unlock(&p->mutex);
> qemu_mutex_lock(&multifd_send_state->mutex);
> p->done = true;
> @@ -475,6 +482,13 @@ static void *multifd_send_thread(void *opaque)
> return NULL;
> }
>
> +static void multifd_init_group(multifd_pages_t *pages)
> +{
> + pages->num = 0;
> + pages->size = migrate_multifd_group();
> + pages->iov = g_malloc0(pages->size * sizeof(struct iovec));
Does that get freed anywhere?
> +}
> +
> int multifd_save_setup(void)
> {
> int thread_count;
> @@ -498,7 +512,7 @@ int multifd_save_setup(void)
> p->quit = false;
> p->id = i;
> p->done = true;
> - p->address = 0;
> + multifd_init_group(&p->pages);
> p->c = socket_send_channel_create();
> if (!p->c) {
> error_report("Error creating a send channel");
> @@ -515,8 +529,23 @@ int multifd_save_setup(void)
>
> static int multifd_send_page(uint8_t *address)
> {
> - int i;
> + int i, j;
> MultiFDSendParams *p = NULL; /* make happy gcc */
> + static multifd_pages_t pages;
> + static bool once;
> +
> + if (!once) {
> + multifd_init_group(&pages);
> + once = true;
> + }
> +
> + pages.iov[pages.num].iov_base = address;
> + pages.iov[pages.num].iov_len = TARGET_PAGE_SIZE;
> + pages.num++;
> +
> + if (pages.num < (pages.size - 1)) {
> + return UINT16_MAX;
That's a very odd magic constant to return.
What's your intention?
> + }
>
> qemu_sem_wait(&multifd_send_state->sem);
> qemu_mutex_lock(&multifd_send_state->mutex);
> @@ -530,7 +559,12 @@ static int multifd_send_page(uint8_t *address)
> }
> qemu_mutex_unlock(&multifd_send_state->mutex);
> qemu_mutex_lock(&p->mutex);
> - p->address = address;
> + p->pages.num = pages.num;
> + for (j = 0; j < pages.size; j++) {
> + p->pages.iov[j].iov_base = pages.iov[j].iov_base;
> + p->pages.iov[j].iov_len = pages.iov[j].iov_len;
> + }
It would seem more logical to update p->pages.num last
This is also a little odd in that iov_len is never really used,
it's always TARGET_PAGE_SIZE.
> + pages.num = 0;
> qemu_mutex_unlock(&p->mutex);
> qemu_sem_post(&p->sem);
What makes sure that any final chunk of pages that was less
than the group size is sent at the end?
Dave
> --
> 2.9.4
>
--
Dr. David Alan Gilbert / address@hidden / Manchester, UK
- Re: [Qemu-devel] [PATCH v5 08/17] migration: Split migration_fd_process_incomming, (continued)
- [Qemu-devel] [PATCH v5 09/17] migration: Start of multiple fd work, Juan Quintela, 2017/07/17
- [Qemu-devel] [PATCH v5 10/17] migration: Create ram_multifd_page, Juan Quintela, 2017/07/17
- [Qemu-devel] [PATCH v5 11/17] migration: Really use multiple pages at a time, Juan Quintela, 2017/07/17
- [Qemu-devel] [PATCH v5 12/17] migration: Send the fd number which we are going to use for this page, Juan Quintela, 2017/07/17
- [Qemu-devel] [PATCH v5 13/17] migration: Create thread infrastructure for multifd recv side, Juan Quintela, 2017/07/17
- [Qemu-devel] [PATCH v5 14/17] migration: Delay the start of reception on main channel, Juan Quintela, 2017/07/17