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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 <weinan.z.li@intel.com>
Signed-off-by: Zhao Yan <yan.y.zhao@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
This commit is contained in:
Zhao Yan 2018-08-01 00:15:09 -04:00 committed by Zhenyu Wang
parent 279ce5d117
commit db47685da1
1 changed files with 10 additions and 1 deletions
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11
drivers/gpu/drm/i915/gvt/cmd_parser.c
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@ -1817,6 +1817,8 @@ 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},
@ -2502,7 +2504,12 @@ 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),
@ -2904,6 +2911,8 @@ static int init_cmd_table(struct intel_gvt *gvt)
info->name);
return -EEXIST;
}
if (cmd_info[i].opcode == OP_MI_NOOP)
mi_noop_index = i;
INIT_HLIST_NODE(&e->hlist);
add_cmd_entry(gvt, e);