Re: [Qemu-devel] [v4 05/13] arch_init: Alloc and free data struct for compression

[Dr. David Alan Gilbert]

* Liang Li (address@hidden) wrote:
> Define the data structure and variables used to do multiple thread
> compression, and add the code to initialize and free them.
> 
> Signed-off-by: Liang Li <address@hidden>
> Signed-off-by: Yang Zhang <address@hidden>

Reviewed-by: Dr. David Alan Gilbert <address@hidden>

> ---
>  arch_init.c | 34 +++++++++++++++++++++++++++++++++-
>  1 file changed, 33 insertions(+), 1 deletion(-)
> 
> diff --git a/arch_init.c b/arch_init.c
> index ed34eb3..87c4947 100644
> --- a/arch_init.c
> +++ b/arch_init.c
> @@ -335,7 +335,12 @@ static uint32_t last_version;
>  static bool ram_bulk_stage;
>  
>  struct CompressParam {
> -    /* To be done */
> +    bool busy;
> +    QEMUFile *file;
> +    QemuMutex mutex;
> +    QemuCond cond;
> +    RAMBlock *block;
> +    ram_addr_t offset;
>  };
>  typedef struct CompressParam CompressParam;
>  
> @@ -345,6 +350,14 @@ struct DecompressParam {
>  typedef struct DecompressParam DecompressParam;
>  
>  static CompressParam *comp_param;
> +/* comp_done_cond is used to wake up the migration thread when
> + * one of the compression threads has finished the compression.
> + * comp_done_lock is used to co-work with comp_done_cond.
> + */
> +static QemuMutex *comp_done_lock;
> +static QemuCond *comp_done_cond;
> +/* The empty QEMUFileOps will be used by file in CompressParam */
> +static const QEMUFileOps empty_ops = { };
>  static bool quit_thread;
>  static DecompressParam *decomp_param;
>  static QemuThread *decompress_threads;
> @@ -379,11 +392,20 @@ void migrate_compress_threads_join(MigrationState *s)
>      thread_count = migrate_compress_threads();
>      for (i = 0; i < thread_count; i++) {
>          qemu_thread_join(s->compress_thread + i);
> +        qemu_fclose(comp_param[i].file);
> +        qemu_mutex_destroy(&comp_param[i].mutex);
> +        qemu_cond_destroy(&comp_param[i].cond);
>      }
> +    qemu_mutex_destroy(comp_done_lock);
> +    qemu_cond_destroy(comp_done_cond);
>      g_free(s->compress_thread);
>      g_free(comp_param);
> +    g_free(comp_done_cond);
> +    g_free(comp_done_lock);
>      s->compress_thread = NULL;
>      comp_param = NULL;
> +    comp_done_cond = NULL;
> +    comp_done_lock = NULL;
>  }
>  
>  void migrate_compress_threads_create(MigrationState *s)
> @@ -397,7 +419,17 @@ void migrate_compress_threads_create(MigrationState *s)
>      thread_count = migrate_compress_threads();
>      s->compress_thread = g_new0(QemuThread, thread_count);
>      comp_param = g_new0(CompressParam, thread_count);
> +    comp_done_cond = g_new0(QemuCond, 1);
> +    comp_done_lock = g_new0(QemuMutex, 1);
> +    qemu_cond_init(comp_done_cond);
> +    qemu_mutex_init(comp_done_lock);
>      for (i = 0; i < thread_count; i++) {
> +        /* com_param[i].file is just used as a dummy buffer to save data, set
> +         * it's ops to empty.
> +         */
> +        comp_param[i].file = qemu_fopen_ops(NULL, &empty_ops);
> +        qemu_mutex_init(&comp_param[i].mutex);
> +        qemu_cond_init(&comp_param[i].cond);
>          qemu_thread_create(s->compress_thread + i, "compress",
>                             do_data_compress, comp_param + i,
>                             QEMU_THREAD_JOINABLE);
> -- 
> 1.9.1
> 
--
Dr. David Alan Gilbert / address@hidden / Manchester, UK