[parisc-linux] Re: Problems with kernel mmap (failing tst-mmap-eofsync in glibc on parisc)

[James Bottomley]

On Sat, 2003-08-23 at 19:22, David S. Miller wrote:
> You're not answering my question :(
> 
> I know that when the case _DOES_ happen, your optimization is
> worthwhile, my question is not about this.  My question is about
> how often does this case happen.

Well the case we're arguing about depends on whether glibc uses mmaped
file descriptors for libio.  If it doesn't (which is how my machine is
configured) then you're right, we never get to loop the i_mmap list
because it's usually empty when flush_dcache_page is called.

The only things I can really come up with are contrived cases with glibc
mmaped file objects...then it is a big win if we open lots of
mappings---which I guess would mainly happen with multi-threaded
applications.  Do you have any applications you'd like me to run
comparisons on?

James