lkml.org 
[lkml]   [2017]   [Aug]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: [PATCH 3/3] IPI: Avoid to use 2 cache lines for one call_single_data
Date
Peter Zijlstra <peterz@infradead.org> writes:
[snip]
> diff --git a/include/linux/smp.h b/include/linux/smp.h
> index 68123c1fe549..8d817cb80a38 100644
> --- a/include/linux/smp.h
> +++ b/include/linux/smp.h
> @@ -14,13 +14,16 @@
> #include <linux/llist.h>
>
> typedef void (*smp_call_func_t)(void *info);
> -struct call_single_data {
> +struct __call_single_data {
> struct llist_node llist;
> smp_call_func_t func;
> void *info;
> unsigned int flags;
> };
>
> +typedef struct __call_single_data call_single_data_t
> + __aligned(sizeof(struct __call_single_data));
> +

Another requirement of the alignment is that it should be the power of
2. Otherwise, for example, if someone adds a field to struct, so that
the size becomes 40 on x86_64. The alignment should be 64 instead of
40.

Best Regards,
Huang, Ying

> /* total number of cpus in this system (may exceed NR_CPUS) */
> extern unsigned int total_cpus;
>
[snip]

\
 
 \ /
  Last update: 2017-08-04 03:29    [W:0.070 / U:0.976 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site