openkylin
/
qemu
mirror of https://gitee.com/openkylin/qemu.git
9
0
Fork 0
Code Issues Projects Releases Wiki Activity

block/qapi: reduce the execution time of qmp_query_blockstats 

In order to reduce the execution time, this patch optimize
the qmp_query_blockstats():
Remove the next_query_bds function.
Remove the bdrv_query_stats function.
Remove some judgement sentence.

The original qmp_query_blockstats calls next_query_bds to get
the next objects in each loops. In the next_query_bds, it checks
the query_nodes and blk. It also call bdrv_query_stats to get
the stats, In the bdrv_query_stats, it checks blk and bs each
times. This waste more times, which may stall the main loop a
bit. And if the disk is too many and donot use the dataplane
feature, this may affect the performance in main loop thread.

This patch removes that two functions, and makes the structure
clearly.

Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.com>
Message-id: 1484467275-27919-3-git-send-email-douly.fnst@cn.fujitsu.com
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[mreitz: Removed duplicate info->value assignment]
Signed-off-by: Max Reitz <mreitz@redhat.com>
This commit is contained in:
Dou Liyang 2017-01-15 16:01:15 +08:00 committed by Max Reitz
parent 20a6d768f5
commit a6baa60807
1 changed files with 28 additions and 43 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

71
block/qapi.c
View File

@ -456,23 +456,6 @@ static BlockStats *bdrv_query_bds_stats(const BlockDriverState *bs,
return s;
}
static BlockStats *bdrv_query_stats(BlockBackend *blk,
const BlockDriverState *bs,
bool query_backing)
{
BlockStats *s;
s = bdrv_query_bds_stats(bs, query_backing);
if (blk) {
s->has_device = true;
s->device = g_strdup(blk_name(blk));
bdrv_query_blk_stats(s->stats, blk);
}
return s;
}
BlockInfoList *qmp_query_block(Error **errp)
{
BlockInfoList *head = NULL, **p_next = &head;
@ -496,42 +479,44 @@ BlockInfoList *qmp_query_block(Error **errp)
return head;
}
static bool next_query_bds(BlockBackend **blk, BlockDriverState **bs,
bool query_nodes)
{
if (query_nodes) {
*bs = bdrv_next_node(*bs);
return !!*bs;
}
*blk = blk_next(*blk);
*bs = *blk ? blk_bs(*blk) : NULL;
return !!*blk;
}
BlockStatsList *qmp_query_blockstats(bool has_query_nodes,
bool query_nodes,
Error **errp)
{
BlockStatsList *head = NULL, **p_next = &head;
BlockBackend *blk = NULL;
BlockDriverState *bs = NULL;
BlockBackend *blk;
BlockDriverState *bs;
/* Just to be safe if query_nodes is not always initialized */
query_nodes = has_query_nodes && query_nodes;
if (has_query_nodes && query_nodes) {
for (bs = bdrv_next_node(NULL); bs; bs = bdrv_next_node(bs)) {
BlockStatsList *info = g_malloc0(sizeof(*info));
AioContext *ctx = bdrv_get_aio_context(bs);
while (next_query_bds(&blk, &bs, query_nodes)) {
BlockStatsList *info = g_malloc0(sizeof(*info));
AioContext *ctx = blk ? blk_get_aio_context(blk)
: bdrv_get_aio_context(bs);
aio_context_acquire(ctx);
info->value = bdrv_query_bds_stats(bs, false);
aio_context_release(ctx);
aio_context_acquire(ctx);
info->value = bdrv_query_stats(blk, bs, !query_nodes);
aio_context_release(ctx);
*p_next = info;
p_next = &info->next;
}
} else {
for (blk = blk_next(NULL); blk; blk = blk_next(blk)) {
BlockStatsList *info = g_malloc0(sizeof(*info));
AioContext *ctx = blk_get_aio_context(blk);
BlockStats *s;
*p_next = info;
p_next = &info->next;
aio_context_acquire(ctx);
s = bdrv_query_bds_stats(blk_bs(blk), true);
s->has_device = true;
s->device = g_strdup(blk_name(blk));
bdrv_query_blk_stats(s->stats, blk);
aio_context_release(ctx);
info->value = s;
*p_next = info;
p_next = &info->next;
}
}
return head;