svn commit: r344562 - head/sys/ufs/ffs
jason.harmening at gmail.com
Tue Feb 26 06:15:01 UTC 2019
On 2/25/19 9:46 PM, Bruce Evans wrote:
> block_size <= PAGE_SIZE is very uncommon for ffs, even on systems with
> pages. MINBSIZE is 4096 in ffs (except in my version, it is 512). The
> default is 32768 in newfs. I consider this excessive and only use it for
> file systems with many files larger than 1GB, but it is the most common
> It is larger than the large page size of 8192.
I think this is a case of filesystem logical block size vs. media sector
size, right? Here we're checking the devvp's block size, which I think
should correspond to the sector size. I'd expect cases of that being
greater than PAGE_SIZE to be uncommon, in fact geli warns when that is
the case. I probably should've made that clearer in the commit message.
> ffs_getpages() already has an almost-never-used special case for small
> block sizes. It uses vnode_pager_generic_getpages() when !use_buf_pager
> and the block_size <= PAGE_SIZE, else vfs_bio_getpages(). But
> block_size <= PAGE_SIZE is unusual, and !use_buf_pager is also unusual,
> and use_buf_pager is mostly a debugging sysctl, so little would be
> lost but using vfs_bio_getpages() unconditionally.
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