CVS commit: src/sys/rump/librump/rumpkern

["Antti Kantee" <pooka%netbsd.org@localhost>]

Module Name:    src
Committed By:   pooka
Date:           Wed Dec  1 20:29:57 UTC 2010

Modified Files:
        src/sys/rump/librump/rumpkern: scheduler.c vm.c

Log Message:
If the pagedaemon cannot free any memory due to not being able to
lock any uvm objects, check if lockholders are currently on CPU
and yield to try very soon again instead of assuming deadlock.

This makes limited-memory kernels perform the same as memory-unlimited
kernels (provided there is a reasonable amount of memory available).
For example, for large file copy off of ffs where the image is
backed on host memory (i.e. no disk i/o, i.e. ideal conditions)
the figures are, per rump kernel memory limit:

3000kB: same
1000kB: 10% slower
500kB:  50% slower

(per pagedaemon code might still be able to use some tweak, though)


To generate a diff of this commit:
cvs rdiff -u -r1.22 -r1.23 src/sys/rump/librump/rumpkern/scheduler.c
cvs rdiff -u -r1.103 -r1.104 src/sys/rump/librump/rumpkern/vm.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.