lkml.org 
[lkml]   [2020]   [Jul]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] sched/fair: provide u64 read for 32-bits arch helper
On Mon, Jul 27, 2020 at 11:59:24AM +0100, vincent.donnefort@arm.com wrote:
> From: Vincent Donnefort <vincent.donnefort@arm.com>
>
> Introducing two macro helpers u64_32read() and u64_32read_set_copy() to
> factorize the u64 vminruntime and last_update_time read on a 32-bits
> architecture. Those new helpers encapsulate smp_rmb() and smp_wmb()
> synchronization and therefore, have a small penalty in set_task_rq_fair()
> and init_cfs_rq().
>
> The choice of using a macro over an inline function is driven by the
> conditional u64 variable copy declarations.
>
> #ifndef CONFIG_64BIT
> u64 [vminruntime|last_update_time]_copy;
> #endif

This lacks a *why*... why did you get up this morning and wrote us this
patch.


\
 
 \ /
  Last update: 2020-07-27 14:38    [W:2.569 / U:0.028 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site