3 ms·

> pretty much limited by the number of open file descriptors the OS allows to handle, if i don't remember wrong this number in FreeBSD is below 10000 by default

> pretty much limited by the number of open file descriptors the OS allows to handle, if i don't remember wrong this number in FreeBSD is below 10000 by default And on Linux inotify is bound by /proc/sys/fs/inotify/max_user_watches. Six of one, half dozen the other. FreeBSD file descriptor limit is arbitrary and can be raised to INT_MAX (2 billion). That should be plenty. > i must say that the kqueue implementation was by far the worst to work at. I agree that the kqueue API is a pain to work with. I haven't tried to do a recursive file monitoring (dropbox-alike) application with it. It seems easy to implement inotify as a thin wrapper around kqueue. Maybe something to do for the FreeBSD linuxulator layer...

SpartanJ 12y ago
> And on Linux inotify is bound by /proc/sys/fs/inotify/max_user_watches. Six of one, half dozen the other. FreeBSD file descriptor limit is arbitrary and can be raised to INT_MAX (2 billion). That should be plenty. Yes, on Linux you're limited to max_user_watches, and you can edit that value, just like you say with kqueue... but you need root access, so for end user applications this is not really a solution. With inotify i use one watch per-folder, with kqueue you need to do it by file ( of course you can watch the folder changes, but you need to keep a copy of the file states in that folder, and then re-stat that files to find out what file was changed, not even close to an ideal solution ). So for example in my use case with inotify i can watch 65536 folders, and with kqueue less than 10000 files ( that could be a single folder! ). Edit: It seems that FreeBSD default a much bigger number for FDs ( https://news.ycombinator.com/item?id=9063893 https://news.ycombinator.com/item?id=9063893 ), so that should suffice a lot of use cases, that's good news for me!
- throwabob214 12y ago
  > With inotify i use one watch per-folder, with kqueue you need to do it by file ( of course you can watch the folder changes, but you need to keep a copy of the file states in that folder, and then re-stat that files to find out what file was changed, not even close to an ideal solution ). So for example in my use case with inotify i can watch 65536 folders, and with kqueue less than 10000 files ( that could be a single folder! ). Ah, I looked at inotify API briefly and did not notice that directory watches return file changes. That does make it easier to use than kevent vnode watches. Mea culpa.

SpartanJ 12y ago

> And on Linux inotify is bound by /proc/sys/fs/inotify/max_user_watches. Six of one, half dozen the other. FreeBSD file descriptor limit is arbitrary and can be raised to INT_MAX (2 billion). That should be plenty. Yes, on Linux you're limited to max_user_watches, and you can edit that value, just like you say with kqueue... but you need root access, so for end user applications this is not really a solution. With inotify i use one watch per-folder, with kqueue you need to do it by file ( of course you can watch the folder changes, but you need to keep a copy of the file states in that folder, and then re-stat that files to find out what file was changed, not even close to an ideal solution ). So for example in my use case with inotify i can watch 65536 folders, and with kqueue less than 10000 files ( that could be a single folder! ). Edit: It seems that FreeBSD default a much bigger number for FDs ( https://news.ycombinator.com/item?id=9063893 https://news.ycombinator.com/item?id=9063893 ), so that should suffice a lot of use cases, that's good news for me!

throwabob214 12y ago
> With inotify i use one watch per-folder, with kqueue you need to do it by file ( of course you can watch the folder changes, but you need to keep a copy of the file states in that folder, and then re-stat that files to find out what file was changed, not even close to an ideal solution ). So for example in my use case with inotify i can watch 65536 folders, and with kqueue less than 10000 files ( that could be a single folder! ). Ah, I looked at inotify API briefly and did not notice that directory watches return file changes. That does make it easier to use than kevent vnode watches. Mea culpa.