tcg: per-thread TCG

[Qemu-devel] [PATCH 02/22] translate-all: remove redundant !tcg_enabled check in dump_exec_info

Posted by Emilio G. Cota 8 years, 3 months ago

This check is redundant because it is already performed by the only
caller of dump_exec_info -- the caller was updated by b7da97eef
("monitor: Check whether TCG is enabled before running the "info jit"
code").

Checking twice wouldn't necessarily be too bad, but here the check also
returns with tb_lock held. So we can either do the check before tb_lock is
acquired, or just get rid of it. Given that it is redundant, I am going
for the latter option.

Signed-off-by: Emilio G. Cota <cota@braap.org>
---
 accel/tcg/translate-all.c | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c
index dfb9f0d..f768681 100644
--- a/accel/tcg/translate-all.c
+++ b/accel/tcg/translate-all.c
@@ -1851,11 +1851,6 @@ void dump_exec_info(FILE *f, fprintf_function cpu_fprintf)
 
     tb_lock();
 
-    if (!tcg_enabled()) {
-        cpu_fprintf(f, "TCG not enabled\n");
-        return;
-    }
-
     target_code_size = 0;
     max_target_code_size = 0;
     cross_page = 0;
-- 
2.7.4

Re: [Qemu-devel] [PATCH 02/22] translate-all: remove redundant !tcg_enabled check in dump_exec_info

Posted by Richard Henderson 8 years, 3 months ago

On 07/08/2017 09:49 PM, Emilio G. Cota wrote:
> This check is redundant because it is already performed by the only
> caller of dump_exec_info -- the caller was updated by b7da97eef
> ("monitor: Check whether TCG is enabled before running the "info jit"
> code").
> 
> Checking twice wouldn't necessarily be too bad, but here the check also
> returns with tb_lock held. So we can either do the check before tb_lock is
> acquired, or just get rid of it. Given that it is redundant, I am going
> for the latter option.
> 
> Signed-off-by: Emilio G. Cota <cota@braap.org>

Reviewed-by: Richard Henderson <rth@twiddle.net>


r~

Re: [Qemu-devel] [PATCH 02/22] translate-all: remove redundant !tcg_enabled check in dump_exec_info

Posted by Thomas Huth 8 years, 3 months ago

On 09.07.2017 09:49, Emilio G. Cota wrote:
> This check is redundant because it is already performed by the only
> caller of dump_exec_info -- the caller was updated by b7da97eef
> ("monitor: Check whether TCG is enabled before running the "info jit"
> code").
> 
> Checking twice wouldn't necessarily be too bad, but here the check also
> returns with tb_lock held. So we can either do the check before tb_lock is
> acquired, or just get rid of it. Given that it is redundant, I am going
> for the latter option.
> 
> Signed-off-by: Emilio G. Cota <cota@braap.org>
> ---
>  accel/tcg/translate-all.c | 5 -----
>  1 file changed, 5 deletions(-)
> 
> diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c
> index dfb9f0d..f768681 100644
> --- a/accel/tcg/translate-all.c
> +++ b/accel/tcg/translate-all.c
> @@ -1851,11 +1851,6 @@ void dump_exec_info(FILE *f, fprintf_function cpu_fprintf)
>  
>      tb_lock();
>  
> -    if (!tcg_enabled()) {
> -        cpu_fprintf(f, "TCG not enabled\n");
> -        return;
> -    }
> -
>      target_code_size = 0;
>      max_target_code_size = 0;
>      cross_page = 0;
> 

Reviewed-by: Thomas Huth <thuth@redhat.com>

Re: [Qemu-devel] [PATCH 02/22] translate-all: remove redundant !tcg_enabled check in dump_exec_info

Posted by Alex Bennée 8 years, 3 months ago

Emilio G. Cota <cota@braap.org> writes:

> This check is redundant because it is already performed by the only
> caller of dump_exec_info -- the caller was updated by b7da97eef
> ("monitor: Check whether TCG is enabled before running the "info jit"
> code").
>
> Checking twice wouldn't necessarily be too bad, but here the check also
> returns with tb_lock held. So we can either do the check before tb_lock is
> acquired, or just get rid of it. Given that it is redundant, I am going
> for the latter option.
>
> Signed-off-by: Emilio G. Cota <cota@braap.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

> ---
>  accel/tcg/translate-all.c | 5 -----
>  1 file changed, 5 deletions(-)
>
> diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c
> index dfb9f0d..f768681 100644
> --- a/accel/tcg/translate-all.c
> +++ b/accel/tcg/translate-all.c
> @@ -1851,11 +1851,6 @@ void dump_exec_info(FILE *f, fprintf_function cpu_fprintf)
>
>      tb_lock();
>
> -    if (!tcg_enabled()) {
> -        cpu_fprintf(f, "TCG not enabled\n");
> -        return;
> -    }
> -
>      target_code_size = 0;
>      max_target_code_size = 0;
>      cross_page = 0;


--
Alex Bennée