From: "Li, ZhenHua" <zhen-h...@hp.com> In virtio-blk module, when there is new request, new req structure will be created by malloc. Use a req pool instead of this, will increase performance;
Increacement: about 5% to 10%. Signed-off-by: Li, ZhenHua <zhen-h...@hp.com> --- hw/block/virtio-blk.c | 87 ++++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 75 insertions(+), 12 deletions(-) diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c index 8a568e5..da5b570 100644 --- a/hw/block/virtio-blk.c +++ b/hw/block/virtio-blk.c @@ -39,6 +39,70 @@ typedef struct VirtIOBlockReq BlockAcctCookie acct; } VirtIOBlockReq; +#define POOL_PAGE 512 +static VirtIOBlockReq * * req_pool; +static char * req_pool_used; +static unsigned long req_pool_size = 0; + +static void remalloc_reqs(void){ + unsigned long old_size = req_pool_size; + unsigned long int i; + char * old_used = req_pool_used; + VirtIOBlockReq * * old_pool = req_pool; + + req_pool_size += POOL_PAGE; + req_pool_used = (char * )malloc(req_pool_size * sizeof(char)); + req_pool = (VirtIOBlockReq * * )malloc(req_pool_size * sizeof(VirtIOBlockReq *)); + + if(old_size != 0){ + memcpy(req_pool_used, old_used, old_size*(sizeof(char))); + memcpy(req_pool, old_pool, old_size*(sizeof(VirtIOBlockReq *))); + } + for(i=old_size; i<req_pool_size; i++){ + req_pool[i] = (VirtIOBlockReq *)malloc(sizeof(VirtIOBlockReq)); + req_pool_used[i] = 0; + } + + if(old_size != 0){ + free(old_used); + free(old_pool); + } +} +static VirtIOBlockReq * req_pool_get_new(void){ + unsigned long int i; + char * used; + VirtIOBlockReq * * req; + + if(req_pool_size == 0){ + remalloc_reqs(); + } + for(i=0, used=req_pool_used, req=req_pool; + i<req_pool_size; i++, used ++, req++){ + if(*used == 0){ + *used = 1; + return *req; + } + } + remalloc_reqs(); + req_pool_used[req_pool_size-POOL_PAGE] = 1; + *req = req_pool[req_pool_size-POOL_PAGE]; + return *req; +} + +static void virtio_blk_free_request(VirtIOBlockReq *req0){ + unsigned long int i; + char * used; + VirtIOBlockReq * * req; + + for(i=0, used=req_pool_used, req=req_pool; + i<req_pool_size; i++, used ++, req++){ + if(*req == req0){ + *used = 0; + } + } +} + + static void virtio_blk_req_complete(VirtIOBlockReq *req, int status) { VirtIOBlock *s = req->dev; @@ -63,7 +127,7 @@ static int virtio_blk_handle_rw_error(VirtIOBlockReq *req, int error, } else if (action == BDRV_ACTION_REPORT) { virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR); bdrv_acct_done(s->bs, &req->acct); - g_free(req); + virtio_blk_free_request(req); } bdrv_error_action(s->bs, action, is_read, error); @@ -84,7 +148,7 @@ static void virtio_blk_rw_complete(void *opaque, int ret) virtio_blk_req_complete(req, VIRTIO_BLK_S_OK); bdrv_acct_done(req->dev->bs, &req->acct); - g_free(req); + virtio_blk_free_request(req); } static void virtio_blk_flush_complete(void *opaque, int ret) @@ -99,25 +163,24 @@ static void virtio_blk_flush_complete(void *opaque, int ret) virtio_blk_req_complete(req, VIRTIO_BLK_S_OK); bdrv_acct_done(req->dev->bs, &req->acct); - g_free(req); + virtio_blk_free_request(req); } - static VirtIOBlockReq *virtio_blk_alloc_request(VirtIOBlock *s) { - VirtIOBlockReq *req = g_malloc(sizeof(*req)); + VirtIOBlockReq *req ; + req = req_pool_get_new(); req->dev = s; req->qiov.size = 0; req->next = NULL; return req; } - static VirtIOBlockReq *virtio_blk_get_request(VirtIOBlock *s) { VirtIOBlockReq *req = virtio_blk_alloc_request(s); if (req != NULL) { if (!virtqueue_pop(s->vq, &req->elem)) { - g_free(req); + virtio_blk_free_request(req); return NULL; } } @@ -142,7 +205,7 @@ static void virtio_blk_handle_scsi(VirtIOBlockReq *req) */ if (req->elem.out_num < 2 || req->elem.in_num < 3) { virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR); - g_free(req); + virtio_blk_free_request(req); return; } @@ -232,7 +295,7 @@ static void virtio_blk_handle_scsi(VirtIOBlockReq *req) stl_p(&req->scsi->data_len, hdr.dxfer_len); virtio_blk_req_complete(req, status); - g_free(req); + virtio_blk_free_request(req); return; #else abort(); @@ -242,7 +305,7 @@ fail: /* Just put anything nonzero so that the ioctl fails in the guest. */ stl_p(&req->scsi->errors, 255); virtio_blk_req_complete(req, status); - g_free(req); + virtio_blk_free_request(req); } typedef struct MultiReqBuffer { @@ -375,7 +438,7 @@ static void virtio_blk_handle_request(VirtIOBlockReq *req, s->blk.serial ? s->blk.serial : "", MIN(req->elem.in_sg[0].iov_len, VIRTIO_BLK_ID_BYTES)); virtio_blk_req_complete(req, VIRTIO_BLK_S_OK); - g_free(req); + virtio_blk_free_request(req); } else if (type & VIRTIO_BLK_T_OUT) { qemu_iovec_init_external(&req->qiov, &req->elem.out_sg[1], req->elem.out_num - 1); @@ -387,7 +450,7 @@ static void virtio_blk_handle_request(VirtIOBlockReq *req, virtio_blk_handle_read(req); } else { virtio_blk_req_complete(req, VIRTIO_BLK_S_UNSUPP); - g_free(req); + virtio_blk_free_request(req); } } -- 1.7.10.4