Re: x86, ARM, PARISC, PPC, MIPS and Sparc folks please run this

[Russell King]

On Wed, Sep 03, 2003 at 08:41:34AM +0100, Jamie Lokier wrote:
> Russell King wrote:
> > > > Multiple mappings of the same object rarely occur in my experience, so
> > > > the resulting performance loss caused by working around the cache and
> > > > writebuffer is something we can live with.
> > > 
> > > Multiple *writable* mappings.   Don't forget about libc et al.
> > 
> > I mean in the same group of threads with the same struct mm, not the whole
> > system.
> 
> Larry means that it's perfectly normal for libc to map the same file
> more than once: you have the code section and the data section.

Code is read-only, data is read-write and is copy on write.  Therefore
its a different scenario.

Practical tests indicate that the vast majority of applications do not
trip the test.

You're right in theory, but I don't particularly care about theory when
its real life which matters.

-- 
Russell King (rmk@xxxxxxxxxxxxxxxx)                The developer of ARM Linux
             http://www.arm.linux.org.uk/personal/aboutme.html

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