[Tarantool-patches] [PATCH v3] refactoring: drop excess 16Kb bss buffer

[Tarantool-patches] [PATCH v3] refactoring: drop excess 16Kb bss buffer

[Sergey Kaplun]

We already have 12Kb thread-safe static buffer
in `lib/small/small/static.h`, that can be used instead of 16Kb
bss buffer in `src/lib/core/backtrace.cc` for backtrace payload.

Closes #4650
---

branch: https://github.com/tarantool/tarantool/tree/skaplun/drop-bss-buff
issue: https://github.com/tarantool/tarantool/issues/4650

 src/lib/core/backtrace.cc | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/lib/core/backtrace.cc b/src/lib/core/backtrace.cc
index 77f77b05c..b5531a596 100644
--- a/src/lib/core/backtrace.cc
+++ b/src/lib/core/backtrace.cc
@@ -47,16 +47,15 @@
 #include <libunwind.h>
 
 #include "small/region.h"
+#include "small/static.h"
 /*
- * We use a global static buffer because it is too late to do any
+ * We use a static buffer interface because it is too late to do any
  * allocation when we are printing backtrace and fiber stack is
  * small.
  */
 
 #define BACKTRACE_NAME_MAX 200
 
-static char backtrace_buf[4096 * 4];
-
 static __thread struct region cache_region;
 static __thread struct mh_i64ptr_t *proc_cache = NULL;
 
@@ -140,8 +139,9 @@ backtrace()
 	unw_getcontext(&unw_context);
 	unw_cursor_t unw_cur;
 	unw_init_local(&unw_cur, &unw_context);
+	char *backtrace_buf = (char *)static_alloc(SMALL_STATIC_SIZE);
 	char *p = backtrace_buf;
-	char *end = p + sizeof(backtrace_buf) - 1;
+	char *end = p + SMALL_STATIC_SIZE - 1;
 	int unw_status;
 	*p = '\0';
 	while ((unw_status = unw_step(&unw_cur)) > 0) {
-- 
2.24.1

Re: [Tarantool-patches] [PATCH v3] refactoring: drop excess 16Kb bss buffer

[Leonid Vasiliev]

LGTM

On 2/13/20 11:06 AM, Sergey Kaplun wrote:
> We already have 12Kb thread-safe static buffer
> in `lib/small/small/static.h`, that can be used instead of 16Kb
> bss buffer in `src/lib/core/backtrace.cc` for backtrace payload.
> 
> Closes #4650
> ---
> 
> branch: https://github.com/tarantool/tarantool/tree/skaplun/drop-bss-buff
> issue: https://github.com/tarantool/tarantool/issues/4650
> 
>   src/lib/core/backtrace.cc | 8 ++++----
>   1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/src/lib/core/backtrace.cc b/src/lib/core/backtrace.cc
> index 77f77b05c..b5531a596 100644
> --- a/src/lib/core/backtrace.cc
> +++ b/src/lib/core/backtrace.cc
> @@ -47,16 +47,15 @@
>   #include <libunwind.h>
>   
>   #include "small/region.h"
> +#include "small/static.h"
>   /*
> - * We use a global static buffer because it is too late to do any
> + * We use a static buffer interface because it is too late to do any
>    * allocation when we are printing backtrace and fiber stack is
>    * small.
>    */
>   
>   #define BACKTRACE_NAME_MAX 200
>   
> -static char backtrace_buf[4096 * 4];
> -
>   static __thread struct region cache_region;
>   static __thread struct mh_i64ptr_t *proc_cache = NULL;
>   
> @@ -140,8 +139,9 @@ backtrace()
>   	unw_getcontext(&unw_context);
>   	unw_cursor_t unw_cur;
>   	unw_init_local(&unw_cur, &unw_context);
> +	char *backtrace_buf = (char *)static_alloc(SMALL_STATIC_SIZE);
>   	char *p = backtrace_buf;
> -	char *end = p + sizeof(backtrace_buf) - 1;
> +	char *end = p + SMALL_STATIC_SIZE - 1;
>   	int unw_status;
>   	*p = '\0';
>   	while ((unw_status = unw_step(&unw_cur)) > 0) {
> 

Re: [Tarantool-patches] [PATCH v3] refactoring: drop excess 16Kb bss buffer

[Vladislav Shpilevoy]

Hi! Thanks for the patch! LGTM.

On 13/02/2020 09:06, Sergey Kaplun wrote:
> We already have 12Kb thread-safe static buffer
> in `lib/small/small/static.h`, that can be used instead of 16Kb
> bss buffer in `src/lib/core/backtrace.cc` for backtrace payload.
> 
> Closes #4650
> ---
> 
> branch: https://github.com/tarantool/tarantool/tree/skaplun/drop-bss-buff
> issue: https://github.com/tarantool/tarantool/issues/4650
> 
>  src/lib/core/backtrace.cc | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)

Re: [Tarantool-patches] [PATCH v3] refactoring: drop excess 16Kb bss buffer

[Kirill Yukhin]

Hello,

On 13 фев 11:06, Sergey Kaplun wrote:
> We already have 12Kb thread-safe static buffer
> in `lib/small/small/static.h`, that can be used instead of 16Kb
> bss buffer in `src/lib/core/backtrace.cc` for backtrace payload.
> 
> Closes #4650
> ---
> 
> branch: https://github.com/tarantool/tarantool/tree/skaplun/drop-bss-buff
> issue: https://github.com/tarantool/tarantool/issues/4650

I've checked your patch into master.

--
Regards, Kirill Yukhin