Upgrade from 5.8 to 5.10 brings FFS to a crawl

[slechtvalk]

I recently upgraded from 5.8 to 5.10 but trying to sync my collection of pictures (about 500gb, just over 200000 files) is sooooo slow... took me about 50 hours to analyse and syncing wasn't even past 1% after 6 hours. so i went back to 5.8 now it goes fast as i was used to...
so something changed in the new version's that slowed things down very much.
(tested this on two different computers)
strange thing is, it started "quick", for this scan like 15MB/s and slows down during the process to about 20kb/s (on local machine 2 usb disks)

i hope the reason for this is going to be found so i can also upgrade to 5.11 :D

[Zenju]

I know of no significant changes between 5.8 and 5.10 that could explain this. Are the two test runs using the same configuration? If the slowdown is caused by file I/O, then a process monitor log can show the difference. If it is caused by high CPU load then process explorer will detect it.

[guydreier]

I'm experiencing the exact same thing. Even after just doing a Compare, after some time, Windows XP Task Manager will show FreeFileSync_Win32.exe using 99% of CPU. Had to revert back to 5.9.

[Zenju]

Ah, so it's a CPU not file I/O bottleneck. Maybe this is what has been reported here:
[404, Invalid URL: https://sourceforge.net/p/freefilesync/bugs/223/]
Alas it seems I scared the original poster off by a snarky remark.
Anyway, I can create a new test version if you help to debug this problem until it's solved. (yes, this may be a little work)

[guydreier]

Ah, so it's a CPU not file I/O bottleneck. Maybe this is what has been reported here:
[404, Invalid URL: https://sourceforge.net/p/freefilesync/bugs/223/]
Alas it seems I scared the original poster off by a snarky remark.
Anyway, I can create a new test version if you help to debug this problem until it's solved. (yes, this may be a little work)

Yes, what I'm experienced is identical to Bug 223. I'd be happy to help.

[Zenju]

I've created a new version for testing, similar like the one discussed in the bug tracker item above. What I need to find out is what FFS is doing, in other words I need to find a code location. So try to reproduce the situation where FFS consumes 100% cpu, then create a couple of memory dumps, and send them to my email address, or post them here as an attachment:
[404, Invalid URL: http://freefilesync.sourceforge.net/FreeFileSync_Win32_test.rar]

(PS, if you are on x64 Windows, you need to start the 32-bit executable in the .rar file directly, else the FFS launcher will select the wrong file)

[Zenju]

I found a piece of code which could explain this behavior, so please also test with the following version and see if the CPU issue is solved:
[404, Invalid URL: http://freefilesync.sourceforge.net/FreeFileSync_5.11_beta_setup.exe]

[Zenju]

I have been able to reproduce the increasing CPU consumption and found the bug. It's been caused by a recent upgrade of an internal library (https://svn.boost.org/trac/boost/ticket/7796) I have updated the beta above with the patch.