> From: "Dr. David Alan Gilbert" <dgilb...@redhat.com>
>
> qemu_get_buffer does a copy, we can avoid the memcpy, and we can then
> remove the extra buffer.
>
> Signed-off-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
> ---
> migration/ram.c | 11 +++--------
> 1 file changed, 3 insertions(+), 8 deletions(-)
>
> diff --git a/migration/ram.c b/migration/ram.c index 994552c..2da3b51 100644
> --- a/migration/ram.c
> +++ b/migration/ram.c
> @@ -286,7 +286,6 @@ static bool quit_comp_thread; static bool
> quit_decomp_thread; static DecompressParam *decomp_param; static
> QemuThread *decompress_threads; -static uint8_t *compressed_data_buf;
>
> static int do_compress_ram_page(CompressParam *param);
>
> @@ -2207,7 +2206,6 @@ void migrate_decompress_threads_create(void)
> thread_count = migrate_decompress_threads();
> decompress_threads = g_new0(QemuThread, thread_count);
> decomp_param = g_new0(DecompressParam, thread_count);
> - compressed_data_buf =
> g_malloc0(compressBound(TARGET_PAGE_SIZE));
> quit_decomp_thread = false;
> for (i = 0; i < thread_count; i++) {
> qemu_mutex_init(&decomp_param[i].mutex);
> @@ -2238,13 +2236,11 @@ void migrate_decompress_threads_join(void)
> }
> g_free(decompress_threads);
> g_free(decomp_param);
> - g_free(compressed_data_buf);
> decompress_threads = NULL;
> decomp_param = NULL;
> - compressed_data_buf = NULL;
> }
>
> -static void decompress_data_with_multi_threads(uint8_t *compbuf,
> +static void decompress_data_with_multi_threads(QEMUFile *f,
> void *host, int len) {
> int idx, thread_count;
> @@ -2253,7 +2249,7 @@ static void
> decompress_data_with_multi_threads(uint8_t *compbuf,
> while (true) {
> for (idx = 0; idx < thread_count; idx++) {
> if (!decomp_param[idx].start) {
> - memcpy(decomp_param[idx].compbuf, compbuf, len);
> + qemu_get_buffer(f, decomp_param[idx].compbuf, len);
> decomp_param[idx].des = host;
> decomp_param[idx].len = len;
> start_decompression(&decomp_param[idx]);
> @@ -2498,8 +2494,7 @@ static int ram_load(QEMUFile *f, void *opaque, int
> version_id)
> ret = -EINVAL;
> break;
> }
> - qemu_get_buffer(f, compressed_data_buf, len);
> - decompress_data_with_multi_threads(compressed_data_buf, host,
> len);
> + decompress_data_with_multi_threads(f, host, len);
> break;
>
> case RAM_SAVE_FLAG_XBZRLE:
> --
I am not familiar with post-copy code, so I just care about this patch.
Good finding, thanks.
Reviewed-by: Liang Li <liang.z...@intel.com>
Liang
