lkml.org 
[lkml]   [2007]   [Dec]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH] Avoid overflows in kernel/time.c
    On Sat, 1 Dec 2007 13:20:47 +0000
    Alan Cox <alan@lxorguk.ukuu.org.uk> wrote:

    > On Sat, 1 Dec 2007 01:33:33 +0100
    > Adrian Bunk <bunk@kernel.org> wrote:
    >
    > > On Thu, Nov 29, 2007 at 04:19:51PM -0800, H. Peter Anvin wrote:
    > > > When the conversion factor between jiffies and milli- or microseconds
    > > > is not a single multiply or divide, as for the case of HZ == 300, we
    > > > currently do a multiply followed by a divide. The intervening
    > > > result, however, is subject to overflows, especially since the
    > > > fraction is not simplified (for HZ == 300, we multiply by 300 and
    > > > divide by 1000).
    > > >...
    > > > kernel/Makefile | 8 +++
    > > > kernel/time.c | 29 +++++++++---
    > > > kernel/timeconst.bc | 123 +++++++++++++++++++++++++++++++++++++++++++++++++++
    > > > 3 files changed, 152 insertions(+), 8 deletions(-)
    > > > create mode 100644 kernel/timeconst.bc
    > > >...
    > >
    > > I have read the hep text, but are the advantages of HZ == 300 really
    > > visible or was this more theoretical?
    >
    > Its visibile for people doing PAL media processing and TV sync work.

    Wake up Alan - NTSC for 300HZ, PAL is OK at 250HZ setting.

    Alan


    \
     
     \ /
      Last update: 2007-12-01 14:41    [W:3.548 / U:0.368 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site