LOG_CPU_MAX_BUF_SHIFT default value depends on BASE_SMALL:
config LOG_CPU_MAX_BUF_SHIFT
default 12 if !BASE_SMALL
default 0 if BASE_SMALL
But, BASE_SMALL is a config of type int and "!BASE_SMALL" is always
evaluated to true whatever is the value of BASE_SMALL.
This patch fixes this by using the correct conditional operator for int
type : BASE_SMALL != 0.
Note: This changes CONFIG_LOG_CPU_MAX_BUF_SHIFT=12 to
CONFIG_LOG_CPU_MAX_BUF_SHIFT=0 for BASE_SMALL defconfigs, but that will
not be a big impact due to this code in kernel/printk/printk.c:
/* by default this will only continue through for large > 64 CPUs */
if (cpu_extra <= __LOG_BUF_LEN / 2)
return;
Systems using CONFIG_BASE_SMALL and having 64+ CPUs should be quite
rare.
John Ogness <[email protected]> (printk reviewer) wrote:
> For printk this will mean that BASE_SMALL systems were probably
> previously allocating/using the dynamic ringbuffer and now they will
> just continue to use the static ringbuffer. Which is fine and saves
> memory (as it should).
Petr Mladek <[email protected]> (printk maintainer) wrote:
> More precisely, it allocated the buffer dynamically when the sum
> of per-CPU-extra space exceeded half of the default static ring
> buffer. This happened for systems with more than 64 CPUs with
> the default config values.
Signed-off-by: Yoann Congal <[email protected]>
Reported-by: Geert Uytterhoeven <[email protected]>
Closes: https://lore.kernel.org/all/CAMuHMdWm6u1wX7efZQf=2XUAHascps76YQac6rdnQGhc8nop_Q@mail.gmail.com/
Reported-by: Vegard Nossum <[email protected]>
Closes: https://lore.kernel.org/all/[email protected]/
Fixes: 4e244c10eab3 ("kconfig: remove unneeded symbol_empty variable")
---
v3->v4:
* Fix BASE_SMALL usage instead of switching to BASE_FULL because
BASE_FULL will be removed in the next patches of this series.
---
init/Kconfig | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/init/Kconfig b/init/Kconfig
index deda3d14135bb..d50ebd2a2ce42 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -734,8 +734,8 @@ config LOG_CPU_MAX_BUF_SHIFT
int "CPU kernel log buffer size contribution (13 => 8 KB, 17 => 128KB)"
depends on SMP
range 0 21
- default 12 if !BASE_SMALL
- default 0 if BASE_SMALL
+ default 0 if BASE_SMALL != 0
+ default 12
depends on PRINTK
help
This option allows to increase the default ring buffer size
--
2.39.2
On Thu, Feb 8, 2024 at 2:10 AM Yoann Congal <[email protected]> wrote:
>
> LOG_CPU_MAX_BUF_SHIFT default value depends on BASE_SMALL:
> config LOG_CPU_MAX_BUF_SHIFT
> default 12 if !BASE_SMALL
> default 0 if BASE_SMALL
> But, BASE_SMALL is a config of type int and "!BASE_SMALL" is always
> evaluated to true whatever is the value of BASE_SMALL.
>
> This patch fixes this by using the correct conditional operator for int
> type : BASE_SMALL != 0.
>
> Note: This changes CONFIG_LOG_CPU_MAX_BUF_SHIFT=12 to
> CONFIG_LOG_CPU_MAX_BUF_SHIFT=0 for BASE_SMALL defconfigs, but that will
> not be a big impact due to this code in kernel/printk/printk.c:
> /* by default this will only continue through for large > 64 CPUs */
> if (cpu_extra <= __LOG_BUF_LEN / 2)
> return;
> Systems using CONFIG_BASE_SMALL and having 64+ CPUs should be quite
> rare.
>
> John Ogness <[email protected]> (printk reviewer) wrote:
> > For printk this will mean that BASE_SMALL systems were probably
> > previously allocating/using the dynamic ringbuffer and now they will
> > just continue to use the static ringbuffer. Which is fine and saves
> > memory (as it should).
>
> Petr Mladek <[email protected]> (printk maintainer) wrote:
> > More precisely, it allocated the buffer dynamically when the sum
> > of per-CPU-extra space exceeded half of the default static ring
> > buffer. This happened for systems with more than 64 CPUs with
> > the default config values.
>
> Signed-off-by: Yoann Congal <[email protected]>
> Reported-by: Geert Uytterhoeven <[email protected]>
> Closes: https://lore.kernel.org/all/CAMuHMdWm6u1wX7efZQf=2XUAHascps76YQac6rdnQGhc8nop_Q@mail.gmail.com/
> Reported-by: Vegard Nossum <[email protected]>
> Closes: https://lore.kernel.org/all/[email protected]/
> Fixes: 4e244c10eab3 ("kconfig: remove unneeded symbol_empty variable")
>
All the Reviewed-by tags are dropped every time, annoyingly.
This is equivalent to v4, which had these tags:
Reviewed-by: Petr Mladek <[email protected]>
Reviewed-by: Masahiro Yamada <[email protected]>
> ---
> v3->v4:
> * Fix BASE_SMALL usage instead of switching to BASE_FULL because
> BASE_FULL will be removed in the next patches of this series.
> ---
> init/Kconfig | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/init/Kconfig b/init/Kconfig
> index deda3d14135bb..d50ebd2a2ce42 100644
> --- a/init/Kconfig
> +++ b/init/Kconfig
> @@ -734,8 +734,8 @@ config LOG_CPU_MAX_BUF_SHIFT
> int "CPU kernel log buffer size contribution (13 => 8 KB, 17 => 128KB)"
> depends on SMP
> range 0 21
> - default 12 if !BASE_SMALL
> - default 0 if BASE_SMALL
> + default 0 if BASE_SMALL != 0
> + default 12
> depends on PRINTK
> help
> This option allows to increase the default ring buffer size
> --
> 2.39.2
>
>
--
Best Regards
Masahiro Yamada
Le 11/02/2024 à 00:41, Masahiro Yamada a écrit :
> On Thu, Feb 8, 2024 at 2:10 AM Yoann Congal <[email protected]> wrote:
>>
>> LOG_CPU_MAX_BUF_SHIFT default value depends on BASE_SMALL:
>> config LOG_CPU_MAX_BUF_SHIFT
>> default 12 if !BASE_SMALL
>> default 0 if BASE_SMALL
>> But, BASE_SMALL is a config of type int and "!BASE_SMALL" is always
>> evaluated to true whatever is the value of BASE_SMALL.
>>
>> This patch fixes this by using the correct conditional operator for int
>> type : BASE_SMALL != 0.
>>
>> Note: This changes CONFIG_LOG_CPU_MAX_BUF_SHIFT=12 to
>> CONFIG_LOG_CPU_MAX_BUF_SHIFT=0 for BASE_SMALL defconfigs, but that will
>> not be a big impact due to this code in kernel/printk/printk.c:
>> /* by default this will only continue through for large > 64 CPUs */
>> if (cpu_extra <= __LOG_BUF_LEN / 2)
>> return;
>> Systems using CONFIG_BASE_SMALL and having 64+ CPUs should be quite
>> rare.
>>
>> John Ogness <[email protected]> (printk reviewer) wrote:
>>> For printk this will mean that BASE_SMALL systems were probably
>>> previously allocating/using the dynamic ringbuffer and now they will
>>> just continue to use the static ringbuffer. Which is fine and saves
>>> memory (as it should).
>>
>> Petr Mladek <[email protected]> (printk maintainer) wrote:
>>> More precisely, it allocated the buffer dynamically when the sum
>>> of per-CPU-extra space exceeded half of the default static ring
>>> buffer. This happened for systems with more than 64 CPUs with
>>> the default config values.
>>
>> Signed-off-by: Yoann Congal <[email protected]>
>> Reported-by: Geert Uytterhoeven <[email protected]>
>> Closes: https://lore.kernel.org/all/CAMuHMdWm6u1wX7efZQf=2XUAHascps76YQac6rdnQGhc8nop_Q@mail.gmail.com/
>> Reported-by: Vegard Nossum <[email protected]>
>> Closes: https://lore.kernel.org/all/[email protected]/
>> Fixes: 4e244c10eab3 ("kconfig: remove unneeded symbol_empty variable")
>>
>
>
>
> All the Reviewed-by tags are dropped every time, annoyingly.
Hi!
Was I supposed to gather these tags from patch version N to patch version N+1?
In that case, I'm sorry, I did not know that :-/
Patch 1/3 is exactly the same but patch 2/3 is equivalent but different. Is there a rule written somewhere about when carrying the tags across revision and when not? (I could not find it)
> This is equivalent to v4, which had these tags:
>
> Reviewed-by: Petr Mladek <[email protected]>
> Reviewed-by: Masahiro Yamada <[email protected]>
Thanks a lot!
>
>> ---
>> v3->v4:
>> * Fix BASE_SMALL usage instead of switching to BASE_FULL because
>> BASE_FULL will be removed in the next patches of this series.
>> ---
>> init/Kconfig | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/init/Kconfig b/init/Kconfig
>> index deda3d14135bb..d50ebd2a2ce42 100644
>> --- a/init/Kconfig
>> +++ b/init/Kconfig
>> @@ -734,8 +734,8 @@ config LOG_CPU_MAX_BUF_SHIFT
>> int "CPU kernel log buffer size contribution (13 => 8 KB, 17 => 128KB)"
>> depends on SMP
>> range 0 21
>> - default 12 if !BASE_SMALL
>> - default 0 if BASE_SMALL
>> + default 0 if BASE_SMALL != 0
>> + default 12
>> depends on PRINTK
>> help
>> This option allows to increase the default ring buffer size
>> --
>> 2.39.2
>>
>>
>
>
> --
> Best Regards
> Masahiro Yamada
--
Yoann Congal
Smile ECS - Tech Expert
On Tue, Feb 13, 2024 at 4:01 AM Yoann Congal <[email protected]> wrote:
>
>
>
> Le 11/02/2024 à 00:41, Masahiro Yamada a écrit :
> > On Thu, Feb 8, 2024 at 2:10 AM Yoann Congal <yoann.congal@smilefr> wrote:
> >>
> >> LOG_CPU_MAX_BUF_SHIFT default value depends on BASE_SMALL:
> >> config LOG_CPU_MAX_BUF_SHIFT
> >> default 12 if !BASE_SMALL
> >> default 0 if BASE_SMALL
> >> But, BASE_SMALL is a config of type int and "!BASE_SMALL" is always
> >> evaluated to true whatever is the value of BASE_SMALL.
> >>
> >> This patch fixes this by using the correct conditional operator for int
> >> type : BASE_SMALL != 0.
> >>
> >> Note: This changes CONFIG_LOG_CPU_MAX_BUF_SHIFT=12 to
> >> CONFIG_LOG_CPU_MAX_BUF_SHIFT=0 for BASE_SMALL defconfigs, but that will
> >> not be a big impact due to this code in kernel/printk/printk.c:
> >> /* by default this will only continue through for large > 64 CPUs */
> >> if (cpu_extra <= __LOG_BUF_LEN / 2)
> >> return;
> >> Systems using CONFIG_BASE_SMALL and having 64+ CPUs should be quite
> >> rare.
> >>
> >> John Ogness <[email protected]> (printk reviewer) wrote:
> >>> For printk this will mean that BASE_SMALL systems were probably
> >>> previously allocating/using the dynamic ringbuffer and now they will
> >>> just continue to use the static ringbuffer. Which is fine and saves
> >>> memory (as it should).
> >>
> >> Petr Mladek <[email protected]> (printk maintainer) wrote:
> >>> More precisely, it allocated the buffer dynamically when the sum
> >>> of per-CPU-extra space exceeded half of the default static ring
> >>> buffer. This happened for systems with more than 64 CPUs with
> >>> the default config values.
> >>
> >> Signed-off-by: Yoann Congal <[email protected]>
> >> Reported-by: Geert Uytterhoeven <[email protected]>
> >> Closes: https://lore.kernel.org/all/CAMuHMdWm6u1wX7efZQf=2XUAHascps76YQac6rdnQGhc8nop_Q@mail.gmail.com/
> >> Reported-by: Vegard Nossum <[email protected]>
> >> Closes: https://lore.kernel.org/all/[email protected]/
> >> Fixes: 4e244c10eab3 ("kconfig: remove unneeded symbol_empty variable")
> >>
> >
> >
> >
> > All the Reviewed-by tags are dropped every time, annoyingly.
>
> Hi!
>
> Was I supposed to gather these tags from patch version N to patch version N+1?
> In that case, I'm sorry, I did not know that :-/
> Patch 1/3 is exactly the same but patch 2/3 is equivalent but different. Is there a rule written somewhere about when carrying the tags across revision and when not? (I could not find it)
I do not know any written rules either.
In my experience, people carry tags
when changes since the previous version are small.
--
Best Regards
Masahiro Yamada