motorhead/qemu
1
0
Fork 0
mirror of https://github.com/Motorhead1991/qemu.git synced 2025-08-04 00:03:54 -06:00
Code Issues Projects Releases Packages Wiki Activity Actions

target-arm: don't generate WFE/YIELD calls for MTTCG

Browse source 
The WFE and YIELD instructions are really only hints and in TCG's case
they were useful to move the scheduling on from one vCPU to the next. In
the parallel context (MTTCG) this just causes an unnecessary cpu_exit
and contention of the BQL.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Alex Bennée 2017-02-23 18:29:24 +00:00
parent 062ba099e0
commit c22edfebff
3 changed files with 29 additions and 6 deletions
Download patch file Download diff file Expand all files Collapse all files

8
target/arm/translate-a64.c
View file

@ -1328,10 +1328,14 @@ static void handle_hint(DisasContext *s, uint32_t insn,
s->is_jmp = DISAS_WFI;
return;
case 1: /* YIELD */
s->is_jmp = DISAS_YIELD;
if (!parallel_cpus) {
s->is_jmp = DISAS_YIELD;
}
return;
case 2: /* WFE */
s->is_jmp = DISAS_WFE;
if (!parallel_cpus) {
s->is_jmp = DISAS_WFE;
}
return;
case 4: /* SEV */
case 5: /* SEVL */