CVSROOT: /cvs
Module name: src
Changes by: b...@cvs.openbsd.org 2012/10/09 09:12:15
Modified files:
sys/kern : kern_bufq.c vfs_bio.c
sys/sys : buf.h
Log message:
bufq write limiting
This change ensures that writes in flight from the buffer cache via bufq
are limited to a high water mark - when the limit is reached the writes sleep
until the amount of IO in flight reaches a low water mark. This avoids the
problem where userland can queue an unlimited amount of asynchronous writes
resulting in the consumption of all/most of our available buffer mapping kva,
and a long queue of writes to the disk.
ok kettenis@, krw@
