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Message-ID: <45887d0a-17d3-40ce-bea5-13fdf9081edd@systematicsw.ab.ca>
Date: Sun, 13 Jul 2025 15:54:13 -0600
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Subject: Re: SLOW ls(1) - cygwin dir lookups with WinNT async requests?
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On 2025-07-12 10:43, Aurélien Couderc via Cygwin wrote:
> Follow up to an old thread,
> Corinna wrote this:
>> Forth, by not trusting Cygwin to do the right thing and adding a lot
>> of unnecessary code for each single ACL, you slow down ls(1) even more
>> on Cygwin, which already gets a beating for being slow.
> 
> Did anyone consider doing the directory lookups piece by piece, as
> async requests?
> Each time read and process a bit of the directory listing, while the
> filesystem requests for the next bits run as Windows async requests?
> That would promote at least parallelism, instead of doing it serially
> like now.

ISTM the assumption is that any directories accessed are already cached by the 
filesystem, whether Linux, Unix, or Windows, so I/O is not required, and even in 
Cygwin's case it only has to return the Windows entries converted to 
dirent/posix_dent in the directory functions (in a 62KB cache buffer holding 100 
entries) for use by coreutils ls(1). Stat and ACL info require additional calls.

-- 
Take care. Thanks, Brian Inglis              Calgary, Alberta, Canada

La perfection est atteinte                   Perfection is achieved
non pas lorsqu'il n'y a plus rien à ajouter  not when there is no more to add
mais lorsqu'il n'y a plus rien à retrancher  but when there is no more to cut
                                 -- Antoine de Saint-Exupéry

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