multithread decompression: Avoid one copy

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 <dgilbert@redhat.com>
Reviewed-by: Liang Li <liang.z.li@intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Message-Id: <1450266458-3178-7-git-send-email-dgilbert@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
This commit is contained in:
Dr. David Alan Gilbert 2015-12-16 11:47:38 +00:00 committed by Amit Shah
parent 063e760a5f
commit c1bc66263c

View File

@ -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: