I/O stats for lmtp, imap and pop

[Olivier ROLAND]

Hi there,

Linux kernel 2.6.20 and later supports per process I/O accounting.
You can access every process/thread's I/O read/write values by using
/proc filesystem.
You can check if your kernel has built with I/O account by just simply
checking /proc/self/io file.
If it exists then you have I/O accounting built-in.

I use that to have real I/O stats for lmtp, imap and pop in Cyrus.
You just need ioconf = yes in your conf to activate I/O stats.
The code autodetect if your kernel support I/O account and disable the
stats if not.

You can find the git branch with the code here :
https://github.com/worldline-messaging/cyrus-imapd/tree/io-stat


Olivier ROLAND
AtoS