Date: Mon, 25 Feb 2019 22:12:52 -0800 From: Jason Harmening <jason.harmening@gmail.com> To: Bruce Evans <brde@optusnet.com.au>, "Jason A. Harmening" <jah@freebsd.org> Cc: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r344562 - head/sys/ufs/ffs Message-ID: <414d1964-f822-33f2-8177-872a4cbedd13@gmail.com> In-Reply-To: <20190226162300.M1437@besplex.bde.org> References: <201902260456.x1Q4uAIu056382@repo.freebsd.org> <20190226162300.M1437@besplex.bde.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On 2/25/19 9:46 PM, Bruce Evans wrote: > > block_size <= PAGE_SIZE is very uncommon for ffs, even on systems with > large > 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 > size. > 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. > > Bruce
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?414d1964-f822-33f2-8177-872a4cbedd13>