lkml.org 
[lkml]   [2008]   [Nov]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: [RFC patch 08/18] cnt32_to_63 should use smp_rmb()
Date
Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> wrote:

> First off, using this macro with get_cycles() is simply buggy, because the
> macro expects _perfect_ order of timestamps, no skew whatsoever, or
> otherwise time could jump.

Erm... Why can't I pass it get_cycles()? Are you saying that sched_clock()
in MN10300 is wrong for it's use of get_cycles() with cnt32_to_63()?

> __x.lo = readl(cnt_lo); /* mmio read */

readl() might insert an extra barrier instruction. Not only that, io_addr
must be unsigned long.

David


\
 
 \ /
  Last update: 2008-11-07 18:09    [W:0.175 / U:0.800 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site