| Message ID | 1500235468-15341-23-git-send-email-cota@braap.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 07/16/2017 10:04 AM, Emilio G. Cota wrote: > Now that all code generation has been converted to check CF_PARALLEL, we can > generate !CF_PARALLEL code without having yet set !parallel_cpus -- > and therefore without having to be in the exclusive region during > cpu_exec_step_atomic. > > While at it, merge cpu_exec_step into cpu_exec_step_atomic. > > Signed-off-by: Emilio G. Cota <cota@braap.org> > --- > accel/tcg/cpu-exec.c | 26 ++++++++++++-------------- > 1 file changed, 12 insertions(+), 14 deletions(-) > > diff --git a/accel/tcg/cpu-exec.c b/accel/tcg/cpu-exec.c > index efe5c85..23e6d2c 100644 > --- a/accel/tcg/cpu-exec.c > +++ b/accel/tcg/cpu-exec.c > @@ -226,7 +226,7 @@ static void cpu_exec_nocache(CPUState *cpu, int max_cycles, > } > #endif > > -static void cpu_exec_step(CPUState *cpu) > +void cpu_exec_step_atomic(CPUState *cpu) > { > CPUClass *cc = CPU_GET_CLASS(cpu); > TranslationBlock *tb; > @@ -239,16 +239,26 @@ static void cpu_exec_step(CPUState *cpu) > if (tb == NULL) { > mmap_lock(); > tb_lock(); > - tb = tb_gen_code(cpu, pc, cs_base, flags, cflags); > + tb = tb_htable_lookup(cpu, pc, cs_base, flags, mask_cf(cflags)); > + if (likely(tb == NULL)) { > + tb = tb_gen_code(cpu, pc, cs_base, flags, cflags); > + } > tb_unlock(); > mmap_unlock(); > } > > + start_exclusive(); > + > + /* Since we got here, we know that parallel_cpus must be true. */ > + parallel_cpus = false; Well, since we've moved parallel_cpus completely out of target/*, we no longer have to set this false, right? I wonder how hard it would be to completely hide this variable now... That said, even that would probably be better as a follow-on cleanup. Reviewed-by: Richard Henderson <rth@twiddle.net> r~
diff --git a/accel/tcg/cpu-exec.c b/accel/tcg/cpu-exec.c index efe5c85..23e6d2c 100644 --- a/accel/tcg/cpu-exec.c +++ b/accel/tcg/cpu-exec.c @@ -226,7 +226,7 @@ static void cpu_exec_nocache(CPUState *cpu, int max_cycles, } #endif -static void cpu_exec_step(CPUState *cpu) +void cpu_exec_step_atomic(CPUState *cpu) { CPUClass *cc = CPU_GET_CLASS(cpu); TranslationBlock *tb; @@ -239,16 +239,26 @@ static void cpu_exec_step(CPUState *cpu) if (tb == NULL) { mmap_lock(); tb_lock(); - tb = tb_gen_code(cpu, pc, cs_base, flags, cflags); + tb = tb_htable_lookup(cpu, pc, cs_base, flags, mask_cf(cflags)); + if (likely(tb == NULL)) { + tb = tb_gen_code(cpu, pc, cs_base, flags, cflags); + } tb_unlock(); mmap_unlock(); } + start_exclusive(); + + /* Since we got here, we know that parallel_cpus must be true. */ + parallel_cpus = false; cc->cpu_exec_enter(cpu); /* execute the generated code */ trace_exec_tb(tb, pc); cpu_tb_exec(cpu, tb); cc->cpu_exec_exit(cpu); + parallel_cpus = true; + + end_exclusive(); } else { /* We may have exited due to another problem here, so we need * to reset any tb_locks we may have taken but didn't release. @@ -262,18 +272,6 @@ static void cpu_exec_step(CPUState *cpu) } } -void cpu_exec_step_atomic(CPUState *cpu) -{ - start_exclusive(); - - /* Since we got here, we know that parallel_cpus must be true. */ - parallel_cpus = false; - cpu_exec_step(cpu); - parallel_cpus = true; - - end_exclusive(); -} - struct tb_desc { target_ulong pc; target_ulong cs_base;
Now that all code generation has been converted to check CF_PARALLEL, we can generate !CF_PARALLEL code without having yet set !parallel_cpus -- and therefore without having to be in the exclusive region during cpu_exec_step_atomic. While at it, merge cpu_exec_step into cpu_exec_step_atomic. Signed-off-by: Emilio G. Cota <cota@braap.org> --- accel/tcg/cpu-exec.c | 26 ++++++++++++-------------- 1 file changed, 12 insertions(+), 14 deletions(-)