When downloading torrent on gigabit connection, speed reach 100MiB/s and number of peers goes > 100 ktorrent interface lags (like 12309) and ktorrent often crashes. Seems that it is related to reaching limit vm.max_map_count, which is by default ~65e3. Console output contain "mmap failed : Cannot allocate memory". Crashes seem to stop after setting "vm.max_map_count = 200000". See links with graphed output of "cat /proc/$(pidof ktorrent)/maps | wc -l" before setting vm.max_map_count to 200e3 and after. 1) default vm.max_map_count, crash in the end: https://0x0.st/spEO.png 2) vm.max_map_count is set 200000, no crash: https://0x0.st/spEg.png
Link to Arch forum topic https://bbs.archlinux.org/viewtopic.php?id=238475
So it seems this was related to virtual memory? Can this now be closed?
KTorrent carshes with default vm.max_map_count this is not ok When vm.max_map_count increased KTorrent not crashing, but it has random freezes - speed goes up to 100MB/s, then freeze for few seconds, then unfreeze and speeds drop, repeat. Also this freeze cause system to lag - video player lag on HD videos
Forgive me if I'm wrong but the OS sets this value right?
(In reply to Justin Zobel from comment #4) > Forgive me if I'm wrong but the OS sets this value right? https://www.kernel.org/doc/Documentation/sysctl/vm.txt The default value is 65536.
Thanks for the information, setting back to reported for investigation.
Thank you for reporting this issue in KDE software. As it has been a while since this issue was reported, can we please ask you to see if you can reproduce the issue with a recent software version? If you can reproduce the issue, please change the status to "REPORTED" when replying. Thank you!
ktorrent 22.08.2 still crashing when vm.max_map_count limit reached