On Fri 28-07-17 11:52:13, Gu Zheng wrote: > > hi,ALL: > when we used the trinity test the fanotify interfaces, it cause many hungtasks. > CONFIG_FANOTIFY_ACCESS_PERMISSIONS=y > the shell is simple: > 1 #!/bin/bash > 2 > 3 while true > 4 do > 5 ./trinity -c fanotify_init -l off -C 2 -X > /dev/null 2>&1 & > 6 sleep 1 > 7 ./trinity -c fanotify_mark -l off -C 2 -X > /dev/null 2>&1 & > 8 sleep 10 > 9 done > we found the trinity enter the D state fastly. > we check the pids'stack <snip> > all progresses are waiting for the response in fanotify_handle_event->fanotify_get_response, > becauseof non-response or killed monitor,so the waitqueue is in blocked state, > then the others will be stucked which use the fanotify_get_response. Yes, this all works as expected. > if we use wait_event_timeout , the responed time can not be guaranteed. > > do you have any ideas? So if your target is sensible trinity testing of fanotify, what you could do is that you would gather all descriptors where fanotify_init() succeeded, watch them and reply to all fanotify events. Alternatively you could just close these descriptors - that would tear down fanotify instance and all events will be auto-accepted. Honza -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR
