Re: [PATCH 1/3] powerpc/cacheinfo: add cacheinfo_teardown, cacheinfo_rebuild

[Michael Ellerman]

On Wed, 2019-06-12 at 04:45:04 UTC, Nathan Lynch wrote:
> Allow external callers to force the cacheinfo code to release all its
> references to cache nodes, e.g. before processing device tree updates
> post-migration, and to rebuild the hierarchy afterward.
> 
> CPU online/offline must be blocked by callers; enforce this.
> 
> Fixes: 410bccf97881 ("powerpc/pseries: Partition migration in the kernel")
> Signed-off-by: Nathan Lynch 
> Reviewed-by: Gautham R. Shenoy 

Series applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/d4aa219a074a5abaf95a756b9f0d190b

cheers

Re: [PATCH 1/3] powerpc/cacheinfo: add cacheinfo_teardown, cacheinfo_rebuild

[Gautham R Shenoy]

On Wed, Jun 12, 2019 at 10:15 AM Nathan Lynch  wrote:
>
> Allow external callers to force the cacheinfo code to release all its
> references to cache nodes, e.g. before processing device tree updates
> post-migration, and to rebuild the hierarchy afterward.
>
> CPU online/offline must be blocked by callers; enforce this.
>
> Fixes: 410bccf97881 ("powerpc/pseries: Partition migration in the kernel")
> Signed-off-by: Nathan Lynch 

Reviewed-by: Gautham R. Shenoy 
> ---
>  arch/powerpc/kernel/cacheinfo.c | 21 +
>  arch/powerpc/kernel/cacheinfo.h |  4 
>  2 files changed, 25 insertions(+)
>
> diff --git a/arch/powerpc/kernel/cacheinfo.c b/arch/powerpc/kernel/cacheinfo.c
> index 862e2890bd3d..42c559efe060 100644
> --- a/arch/powerpc/kernel/cacheinfo.c
> +++ b/arch/powerpc/kernel/cacheinfo.c
> @@ -896,4 +896,25 @@ void cacheinfo_cpu_offline(unsigned int cpu_id)
> if (cache)
> cache_cpu_clear(cache, cpu_id);
>  }
> +
> +void cacheinfo_teardown(void)
> +{
> +   unsigned int cpu;
> +
> +   lockdep_assert_cpus_held();
> +
> +   for_each_online_cpu(cpu)
> +   cacheinfo_cpu_offline(cpu);
> +}
> +
> +void cacheinfo_rebuild(void)
> +{
> +   unsigned int cpu;
> +
> +   lockdep_assert_cpus_held();
> +
> +   for_each_online_cpu(cpu)
> +   cacheinfo_cpu_online(cpu);
> +}
> +
>  #endif /* (CONFIG_PPC_PSERIES && CONFIG_SUSPEND) || CONFIG_HOTPLUG_CPU */
> diff --git a/arch/powerpc/kernel/cacheinfo.h b/arch/powerpc/kernel/cacheinfo.h
> index 955f5e999f1b..52bd3fc6642d 100644
> --- a/arch/powerpc/kernel/cacheinfo.h
> +++ b/arch/powerpc/kernel/cacheinfo.h
> @@ -6,4 +6,8 @@
>  extern void cacheinfo_cpu_online(unsigned int cpu_id);
>  extern void cacheinfo_cpu_offline(unsigned int cpu_id);
>
> +/* Allow migration/suspend to tear down and rebuild the hierarchy. */
> +extern void cacheinfo_teardown(void);
> +extern void cacheinfo_rebuild(void);
> +
>  #endif /* _PPC_CACHEINFO_H */
> --
> 2.20.1
>


-- 
Thanks and Regards
gautham.

[PATCH 1/3] powerpc/cacheinfo: add cacheinfo_teardown, cacheinfo_rebuild

[Nathan Lynch]

Allow external callers to force the cacheinfo code to release all its
references to cache nodes, e.g. before processing device tree updates
post-migration, and to rebuild the hierarchy afterward.

CPU online/offline must be blocked by callers; enforce this.

Fixes: 410bccf97881 ("powerpc/pseries: Partition migration in the kernel")
Signed-off-by: Nathan Lynch 
---
 arch/powerpc/kernel/cacheinfo.c | 21 +
 arch/powerpc/kernel/cacheinfo.h |  4 
 2 files changed, 25 insertions(+)

diff --git a/arch/powerpc/kernel/cacheinfo.c b/arch/powerpc/kernel/cacheinfo.c
index 862e2890bd3d..42c559efe060 100644
--- a/arch/powerpc/kernel/cacheinfo.c
+++ b/arch/powerpc/kernel/cacheinfo.c
@@ -896,4 +896,25 @@ void cacheinfo_cpu_offline(unsigned int cpu_id)
if (cache)
cache_cpu_clear(cache, cpu_id);
 }
+
+void cacheinfo_teardown(void)
+{
+   unsigned int cpu;
+
+   lockdep_assert_cpus_held();
+
+   for_each_online_cpu(cpu)
+   cacheinfo_cpu_offline(cpu);
+}
+
+void cacheinfo_rebuild(void)
+{
+   unsigned int cpu;
+
+   lockdep_assert_cpus_held();
+
+   for_each_online_cpu(cpu)
+   cacheinfo_cpu_online(cpu);
+}
+
 #endif /* (CONFIG_PPC_PSERIES && CONFIG_SUSPEND) || CONFIG_HOTPLUG_CPU */
diff --git a/arch/powerpc/kernel/cacheinfo.h b/arch/powerpc/kernel/cacheinfo.h
index 955f5e999f1b..52bd3fc6642d 100644
--- a/arch/powerpc/kernel/cacheinfo.h
+++ b/arch/powerpc/kernel/cacheinfo.h
@@ -6,4 +6,8 @@
 extern void cacheinfo_cpu_online(unsigned int cpu_id);
 extern void cacheinfo_cpu_offline(unsigned int cpu_id);
 
+/* Allow migration/suspend to tear down and rebuild the hierarchy. */
+extern void cacheinfo_teardown(void);
+extern void cacheinfo_rebuild(void);
+
 #endif /* _PPC_CACHEINFO_H */
-- 
2.20.1