The following commit has been merged into the x86/apic branch of tip:
Commit-ID: 429bb0269058e2e1f4ab69a0d33d374933aa15b9
Gitweb: https://git.kernel.org/tip/429bb0269058e2e1f4ab69a0d33d374933aa15b9
Author: Ingo Molnar <[email protected]>
AuthorDate: Mon, 26 Feb 2024 12:07:31 +01:00
Committer: Ingo Molnar <[email protected]>
CommitterDate: Mon, 26 Feb 2024 12:13:40 +01:00
smp: Provide 'setup_max_cpus' definition on UP too
This was already defined locally by init/main.c, but let's make
it generic, as arch/x86/kernel/cpu/topology.c is going to make
use of it to have more uniform code.
[ Keep it a C variable, not a define, because there's
some namespace overlap for the 'setup_max_cpus' token
in existing function argument names. ]
Reviewed-by: Thomas Gleixner <[email protected]>
Cc: [email protected]
Signed-off-by: Ingo Molnar <[email protected]>
--
---
include/linux/smp.h | 2 ++
init/main.c | 1 -
2 files changed, 2 insertions(+), 1 deletion(-)
diff --git a/include/linux/smp.h b/include/linux/smp.h
index e87520d..5a5985f 100644
--- a/include/linux/smp.h
+++ b/include/linux/smp.h
@@ -218,6 +218,8 @@ smp_call_function_any(const struct cpumask *mask, smp_call_func_t func,
static inline void kick_all_cpus_sync(void) { }
static inline void wake_up_all_idle_cpus(void) { }
+static const unsigned int setup_max_cpus = 0;
+
#ifdef CONFIG_UP_LATE_INIT
extern void __init up_late_init(void);
static inline void smp_init(void) { up_late_init(); }
diff --git a/init/main.c b/init/main.c
index e24b078..5644bb1 100644
--- a/init/main.c
+++ b/init/main.c
@@ -603,7 +603,6 @@ static int __init rdinit_setup(char *str)
__setup("rdinit=", rdinit_setup);
#ifndef CONFIG_SMP
-static const unsigned int setup_max_cpus = NR_CPUS;
static inline void setup_nr_cpu_ids(void) { }
static inline void smp_prepare_cpus(unsigned int maxcpus) { }
#endif
On Mon, Feb 26, 2024 at 11:48:06AM -0000, tip-bot2 for Ingo Molnar wrote:
> The following commit has been merged into the x86/apic branch of tip:
>
> Commit-ID: 429bb0269058e2e1f4ab69a0d33d374933aa15b9
> Gitweb: https://git.kernel.org/tip/429bb0269058e2e1f4ab69a0d33d374933aa15b9
> Author: Ingo Molnar <[email protected]>
> AuthorDate: Mon, 26 Feb 2024 12:07:31 +01:00
> Committer: Ingo Molnar <[email protected]>
> CommitterDate: Mon, 26 Feb 2024 12:13:40 +01:00
>
> smp: Provide 'setup_max_cpus' definition on UP too
>
> This was already defined locally by init/main.c, but let's make
> it generic, as arch/x86/kernel/cpu/topology.c is going to make
> use of it to have more uniform code.
>
> [ Keep it a C variable, not a define, because there's
> some namespace overlap for the 'setup_max_cpus' token
> in existing function argument names. ]
>
> Reviewed-by: Thomas Gleixner <[email protected]>
> Cc: [email protected]
> Signed-off-by: Ingo Molnar <[email protected]>
> --
> ---
> include/linux/smp.h | 2 ++
> init/main.c | 1 -
> 2 files changed, 2 insertions(+), 1 deletion(-)
That one needs some work:
$ grep setup_max_cpus 13-37-17-randconfig-x86_64-2517.log
..
/include/linux/smp.h:221:27: warning: ‘setup_max_cpus’ defined but not used [-Wunused-const-variable=]
$ grep setup_max_cpus 13-37-17-randconfig-x86_64-2517.log | wc -l
122
very noisy.
randconfig attached.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
On Mon, Feb 26 2024 at 11:48, tip-bot2 for Ingo Molnar wrote:
> --- a/include/linux/smp.h
> +++ b/include/linux/smp.h
> @@ -218,6 +218,8 @@ smp_call_function_any(const struct cpumask *mask, smp_call_func_t func,
> static inline void kick_all_cpus_sync(void) { }
> static inline void wake_up_all_idle_cpus(void) { }
>
> +static const unsigned int setup_max_cpus = 0;
Oops. I missed that when looking at the patch. This is in a header file
and will be instantiated a gazillion times where ever the header is
included. It want's to be a define, no?
Thanks,
tglx
---
--- a/include/linux/smp.h
+++ b/include/linux/smp.h
@@ -218,7 +218,7 @@ smp_call_function_any(const struct cpuma
static inline void kick_all_cpus_sync(void) { }
static inline void wake_up_all_idle_cpus(void) { }
-static const unsigned int setup_max_cpus = 0;
+#define setup_max_cpus (0)
#ifdef CONFIG_UP_LATE_INIT
extern void __init up_late_init(void);
* Borislav Petkov <[email protected]> wrote:
> On Mon, Feb 26, 2024 at 11:48:06AM -0000, tip-bot2 for Ingo Molnar wrote:
> > The following commit has been merged into the x86/apic branch of tip:
> >
> > Commit-ID: 429bb0269058e2e1f4ab69a0d33d374933aa15b9
> > Gitweb: https://git.kernel.org/tip/429bb0269058e2e1f4ab69a0d33d374933aa15b9
> > Author: Ingo Molnar <[email protected]>
> > AuthorDate: Mon, 26 Feb 2024 12:07:31 +01:00
> > Committer: Ingo Molnar <[email protected]>
> > CommitterDate: Mon, 26 Feb 2024 12:13:40 +01:00
> >
> > smp: Provide 'setup_max_cpus' definition on UP too
> >
> > This was already defined locally by init/main.c, but let's make
> > it generic, as arch/x86/kernel/cpu/topology.c is going to make
> > use of it to have more uniform code.
> >
> > [ Keep it a C variable, not a define, because there's
> > some namespace overlap for the 'setup_max_cpus' token
> > in existing function argument names. ]
> >
> > Reviewed-by: Thomas Gleixner <[email protected]>
> > Cc: [email protected]
> > Signed-off-by: Ingo Molnar <[email protected]>
> > --
> > ---
> > include/linux/smp.h | 2 ++
> > init/main.c | 1 -
> > 2 files changed, 2 insertions(+), 1 deletion(-)
>
> That one needs some work:
>
> $ grep setup_max_cpus 13-37-17-randconfig-x86_64-2517.log
> ...
> ./include/linux/smp.h:221:27: warning: ‘setup_max_cpus’ defined but not used [-Wunused-const-variable=]
> $ grep setup_max_cpus 13-37-17-randconfig-x86_64-2517.log | wc -l
> 122
>
> very noisy.
Yeah, a bit sad.
So I resolved this all with using #define and (first) fixing a namespace
collision that broke with the #define:
4c8a49854130 smp: Avoid 'setup_max_cpus' namespace collision/shadowing
3c2f8859ae1c smp: Provide 'setup_max_cpus' definition on UP too
6be4ec29685c x86/apic: Build the x86 topology enumeration functions on UP APIC builds too
Thanks,
Ingo