From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Zhao Yan Date: Fri, 14 Sep 2018 16:10:20 +0800 Subject: [PATCH] drm/i915/gvt: add a fastpath for cmd parsing on MI_NOOP MI_NOOP is a common command appearing in almost all command buffers, put it into a fastpath can improve perfomance, especially in command buffers contains lots of MI_NOOPs (0s). Take glmark2 as an example, 3% performance increase is observed after introduced this patch. Meanwhile, in case where abundant in MI_NOOPs, up to 12% performance increase is measured. v2: use lowercase for index of MI_NOOP in cmd_info (zhenyu wang) Signed-off-by: Li Weinan Signed-off-by: Zhao Yan Signed-off-by: Zhenyu Wang Reviewed-by: Zhao Yakui Reviewed-by: He, Min --- drivers/gpu/drm/i915/gvt/cmd_parser.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/gvt/cmd_parser.c b/drivers/gpu/drm/i915/gvt/cmd_parser.c index c22a786df095..cdccccf787b5 100644 --- a/drivers/gpu/drm/i915/gvt/cmd_parser.c +++ b/drivers/gpu/drm/i915/gvt/cmd_parser.c @@ -1840,6 +1840,8 @@ static int cmd_handler_mi_batch_buffer_start(struct parser_exec_state *s) return ret; } +static int mi_noop_index; + static struct cmd_info cmd_info[] = { {"MI_NOOP", OP_MI_NOOP, F_LEN_CONST, R_ALL, D_ALL, 0, 1, NULL}, @@ -2525,7 +2527,12 @@ static int cmd_parser_exec(struct parser_exec_state *s) cmd = cmd_val(s, 0); - info = get_cmd_info(s->vgpu->gvt, cmd, s->ring_id); + /* fastpath for MI_NOOP */ + if (cmd == MI_NOOP) + info = &cmd_info[mi_noop_index]; + else + info = get_cmd_info(s->vgpu->gvt, cmd, s->ring_id); + if (info == NULL) { gvt_vgpu_err("unknown cmd 0x%x, opcode=0x%x, addr_type=%s, ring %d, workload=%p\n", cmd, get_opcode(cmd, s->ring_id), @@ -2955,6 +2962,8 @@ static int init_cmd_table(struct intel_gvt *gvt) kfree(e); return -EEXIST; } + if (cmd_info[i].opcode == OP_MI_NOOP) + mi_noop_index = i; INIT_HLIST_NODE(&e->hlist); add_cmd_entry(gvt, e); -- https://clearlinux.org