Messages in this thread | | | Date | Wed, 3 Sep 2003 19:05:19 +0100 | From | Russell King <> | Subject | Re: x86, ARM, PARISC, PPC, MIPS and Sparc folks please run this |
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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@arm.linux.org.uk) The developer of ARM Linux http://www.arm.linux.org.uk/personal/aboutme.html
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