On Mon, Aug 30, 2010 at 02:16:55PM +0300, Sagi Ben-Akiva wrote: >For the last couple of weeks I'm trying to identify the cause for cygwin >slowdown on x64 machines which was reported by David Morgan about 6 >months ago. > >Using cvsps I was able to generate a patchset which contains all the >changes between those 2 revisions. >I then applied the changes one by one and built cygwin1.dll for each >change, then I ran my test script again for each cygwin1.dll version and >I found that the change to winsup/cygwin/dcrt0.cc from '2006/03/12 >23:57:03' introduce this issue. > >The log for this change is : > >* dcrt0.cc (dll_crt0_0): Call sigproc_init during init startup. >(_dll_crt0): Don't worry about sync_startup. Just wait for sigthread here. > >This change includes 2 different sub-changes : >1. Moving the call to sigproc_init from dll_crt0_1 function to >dll_crt0_0 - which doesn't affect performance. > >2. a. Moving the call to wait_for_sigthread from dll_crt0_1 to _dll_crt0 >which calls dll_crt0_1. > b. Deleting the call to WaitForSingleObject, > i.e. : "Don't worry about sync_startup" > >I can confirm that the 2nd sub-change is the cause for the slowdown. > >Any help will be appreciated.
I rewrote the signal initialization stuff today and have generated a new snapshot. Please let me know if this works better for you. I haven't actually tried to run a fork per sec. test yet so there may be other lurking problems. http://cygwin.com/snapshots/ cgf -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
