lkml.org 
[lkml]   [2015]   [Oct]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [v3, 3/3] MIPS: VDSO: Add implementations of gettimeofday() and clock_gettime()
You can not use R4K CP0_count in SMP (multicore) without core-specific 
adjustment.
After first power-saving with core clock off or core down the values in
CP0_count
in different cores are absolutely different.

Until you include in system a patch like
http://patchwork.linux-mips.org/patch/10871/

"MIPS: Setup an instruction emulation in VDSO protected page
instead of user stack"

which creates a per-thread memory and put into that memory an adjustment
value
(which can be changed during re-schedule to another core), the use of
R4K counter is incorrect
in SMP environment.

Note: It is also possible to setup and maintain a per-core page with
that value too as
an alternative variant for adjustment.


\
 
 \ /
  Last update: 2015-10-23 04:01    [W:0.156 / U:0.532 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site