* Juan Quintela (quint...@redhat.com) wrote:
> Reorder the structures so we can know if the fields are:
> - Read only
> - Their own locking (i.e. sems)
> - Protected by 'mutex'
> - Only for the multifd channel
>
> Signed-off-by: Juan Quintela <quint...@redhat.com>
> ---
> migration/multifd.h | 86 +++++++++++++++++++++++++++------------------
> 1 file changed, 51 insertions(+), 35 deletions(-)
>
> diff --git a/migration/multifd.h b/migration/multifd.h
> index 7d0effcb03..f1f88c6737 100644
> --- a/migration/multifd.h
> +++ b/migration/multifd.h
> @@ -65,7 +65,9 @@ typedef struct {
> } MultiFDPages_t;
>
> typedef struct {
> - /* this fields are not changed once the thread is created */
> + /* Fiields are only written at creating/deletion time */
> + /* No lock required for them, they are read only */
> +
> /* channel number */
> uint8_t id;
> /* channel thread name */
> @@ -74,37 +76,45 @@ typedef struct {
> QemuThread thread;
> /* communication channel */
> QIOChannel *c;
> - /* sem where to wait for more work */
> - QemuSemaphore sem;
> - /* this mutex protects the following parameters */
> - QemuMutex mutex;
> - /* is this channel thread running */
> - bool running;
> - /* should this thread finish */
> - bool quit;
> /* is the yank function registered */
> bool registered_yank;
> + /* packet allocated len */
> + uint32_t packet_len;
> +
> + /* sem where to wait for more work */
> + QemuSemaphore sem;
> + /* syncs main thread and channels */
> + QemuSemaphore sem_sync;
> +
> + /* this mutex protects the following parameters */
> + QemuMutex mutex;
> + /* is this channel thread running */
> + bool running;
> + /* should this thread finish */
> + bool quit;
> + /* multifd flags for each packet */
> + uint32_t flags;
> + /* global number of generated multifd packets */
> + uint64_t packet_num;
Is there a way to explain why packet_num, being global, is inside
SendParams? I understand why num_packets is - because
that's per channel; so why is a global isnide the params
(and having two things with almost the same name is very confusing!)
Dave
> /* thread has work to do */
> int pending_job;
> - /* array of pages to sent */
> + /* array of pages to sent.
> + * The owner of 'pages' depends of 'pending_job' value:
> + * pending_job == 0 -> migration_thread can use it.
> + * pending_job != 0 -> multifd_channel can use it.
> + */
> MultiFDPages_t *pages;
> - /* packet allocated len */
> - uint32_t packet_len;
> +
> + /* thread local variables. No locking required */
> +
> /* pointer to the packet */
> MultiFDPacket_t *packet;
> - /* multifd flags for each packet */
> - uint32_t flags;
> /* size of the next packet that contains pages */
> uint32_t next_packet_size;
> - /* global number of generated multifd packets */
> - uint64_t packet_num;
> - /* thread local variables */
> /* packets sent through this channel */
> uint64_t num_packets;
> /* non zero pages sent through this channel */
> uint64_t total_normal_pages;
> - /* syncs main thread and channels */
> - QemuSemaphore sem_sync;
> /* buffers to send */
> struct iovec *iov;
> /* number of iovs used */
> @@ -118,7 +128,9 @@ typedef struct {
> } MultiFDSendParams;
>
> typedef struct {
> - /* this fields are not changed once the thread is created */
> + /* Fiields are only written at creating/deletion time */
> + /* No lock required for them, they are read only */
> +
> /* channel number */
> uint8_t id;
> /* channel thread name */
> @@ -127,31 +139,35 @@ typedef struct {
> QemuThread thread;
> /* communication channel */
> QIOChannel *c;
> + /* packet allocated len */
> + uint32_t packet_len;
> +
> + /* syncs main thread and channels */
> + QemuSemaphore sem_sync;
> +
> /* this mutex protects the following parameters */
> QemuMutex mutex;
> /* is this channel thread running */
> bool running;
> /* should this thread finish */
> bool quit;
> + /* multifd flags for each packet */
> + uint32_t flags;
> + /* global number of generated multifd packets */
> + uint64_t packet_num;
> +
> + /* thread local variables. No locking required */
> +
> + /* pointer to the packet */
> + MultiFDPacket_t *packet;
> + /* size of the next packet that contains pages */
> + uint32_t next_packet_size;
> + /* packets sent through this channel */
> + uint64_t num_packets;
> /* ramblock host address */
> uint8_t *host;
> - /* packet allocated len */
> - uint32_t packet_len;
> - /* pointer to the packet */
> - MultiFDPacket_t *packet;
> - /* multifd flags for each packet */
> - uint32_t flags;
> - /* global number of generated multifd packets */
> - uint64_t packet_num;
> - /* thread local variables */
> - /* size of the next packet that contains pages */
> - uint32_t next_packet_size;
> - /* packets sent through this channel */
> - uint64_t num_packets;
> /* non zero pages recv through this channel */
> uint64_t total_normal_pages;
> - /* syncs main thread and channels */
> - QemuSemaphore sem_sync;
> /* buffers to recv */
> struct iovec *iov;
> /* Pages that are not zero */
> --
> 2.35.1
>
--
Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
