Re: Windows performance / threading file access

From: pro-logic <pro-logic@optusnet.com.au>
Date: Oct 15, 2013, 22:22 UTC
Message-ID: <3bb056f6-5f8b-486e-8e5e-9bf541bd0d0b@googlegroups.com>
In-Reply-To: <CAHOQ7J_sNnajm9M+QUd-QwkQGP2vOidzAW5_5EzsdwBGTDCnSA@mail.gmail.com>

I also get fairly slow performance out of the checkout / reset operations on windows.

This discussion got me trying to work out what's taking so long on windows. To help I used killcache [1] to flush the HDD cache and Very Sleepy [2] to profile the code. I couldn't use the GIT_TRACE_PERFORMANCE [3] patch as that seems to only work on script commands, and in my case I just get a result of "335 seconds git reset --hard head" from the log.

After running killcache I ran very sleepy connected to git, and according to the profile: 95.5% of the time is spent in do_lstat (mingw.c) / NtQueryFullAttributeFile (ntdll)

For fun, not knowing if I would break anything or not (it probably does), I wrapped the entire unpack_trees method in the fscache [4] and the total git reset --hard head time fell from 335 seconds to 28 seconds, a 11x improvement.

Albert [1] https://github.com/sgraham/killcache [2] http://www.codersnotes.com/sleepy [3] https://github.com/msysgit/git/pull/38 [4] https://github.com/msysgit/git/pull/94

-- 
-- 
*** Please reply-to-all at all times ***
*** (do not pretend to know who is subscribed and who is not) ***
*** Please avoid top-posting. ***
The msysGit Wiki is here: https://github.com/msysgit/msysgit/wiki - Github accounts are free.

You received this message because you are subscribed to the Google
Groups "msysGit" group.
To post to this group, send email to msysgit@googlegroups.com
To unsubscribe from this group, send email to
msysgit+unsubscribe@googlegroups.com
For more options, and view previous threads, visit this group at
http://groups.google.com/group/msysgit?hl=en_US?hl=en

--- 
You received this message because you are subscribed to the Google Groups "msysGit" group.
To unsubscribe from this group and stop receiving emails from it, send an email to msysgit+unsubscribe@googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.