Confusing BKVASIZE
Jung-uk Kim
jkim at niksun.com
Mon Aug 4 11:49:51 PDT 2003
As you know, BKVASIZE is 16K:
http://www.freebsd.org/cgi/cvsweb.cgi/src/sys/sys/param.h#rev1.63
Default UFS block size is also 16K:
http://www.freebsd.org/cgi/cvsweb.cgi/src/sbin/newfs/newfs.c#rev1.46
But src/sys/sys/param.h says:
'The default (BKVASIZE) is 16384, roughly 2x the block size
used by a normal UFS filesystem.'
This is not true any more and it is really confusing. In fact, I found many
confusing instances, e.g.
src/sys/kern/vfs_bio.c:
/*
* To support extreme low-memory systems, make sure hidirtybuffers cannot
* eat up all available buffer space. This occurs when our minimum cannot
* be met. We try to size hidirtybuffers to 3/4 our buffer space assuming
* BKVASIZE'd (8K) buffers.
*/
I cannot believe comments any more and this is clearly error-prone. :-(
Can anybody clean this mess up?
Thanks,
Jung-uk Kim
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