Re: A Simple Real World Benchmark for cygwin

[Christopher Faylor <cgf@redhat.com>]

On Mon, Sep 02, 2002 at 11:34:11PM +0200, Dan Vasaru wrote:
>cgf> or investigate the code and offer ways to speed it up.
>
>Here's a potential speedup for non-NTFS symlinks:
>
>The check_shortcut function in shortcut.c calls CoInitialize/CoUninitialize
>for *every* .LNK it needs to check on non EA filesystems.
>
>I ran a small test on my computer, calling check_shortcut 1000 times.
>When I moved the calls to CoInitialze/CoUnitialize outside the
>check_shortcut function, the function throughput increased from 59 calls/sec
>to 960 calls/sec.
>
>As it turns out, CoInit...CoUninit costs up to 20 msecs on my system.
>
>So my suggestion is that the CoInit../CoUnit... calls be moved to another
>spot, to be called once per thread.
>
>
>Dan.
>
>PS. This patch made no difference what-so-ever on the timing results of the
>cygbench configure on my NTFS disks; then again, it may help FATxx/Samba/NFS
>people.

Only if there are a lot of symlinks, it seems.  Otherwise the code would never
be hit.  And indiscriminately setting it once for each thread could have some
negative ramifications when the program isn't manipulating any symlinks.

It's a good suggestion, nonetheless.

Corinna, this is your code, what do you think?  Maybe a per-thread
"initialized_yet?" global would be useful here.

cgf

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