On Tue, 13 Jul 2010 15:34:12 -0700
Jerry Toung <[email protected]> wrote:
> Hello List,
> I am on 8.0 RELEASE amd64. My system has 2 RAID arrays connected to 2
> separate
> controllers.
> My I/O throughput tests jumped by ~100MB/sec on both channels, when I
> commented out the
> following piece of code from kern/vfs_bio.c
>
> void
> waitrunningbufspace(void)
> {
> /*
> mtx_lock(&rbreqlock);
> while (runningbufspace > hirunningspace) {
> ++runningbufreq;
> msleep(&runningbufreq, &rbreqlock, PVM, "wdrain", 0);
> }
> mtx_unlock(&rbreqlock);
> */
> }
>
> so far, I can't observe any side effects of not running it. Am I on a time
> bomb?
>
Rather than commenting out the code try setting the sysctl
vfs.hirunningspace to various powers-of-two. Default seems to be
1MB. I just changed it on the command line as a test to 2MB.
You can do this in /etc/sysctl.conf.
--
Gary Jennejohn
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