Date: Sat, 11 Feb 2012 04:20:22 +1100 (EST) From: Bruce Evans <brde@optusnet.com.au> To: Sergey Kandaurov <pluknet@FreeBSD.org> Cc: svn-src-head@FreeBSD.org, svn-src-all@FreeBSD.org, src-committers@FreeBSD.org, Ed Schouten <ed@FreeBSD.org> Subject: Re: svn commit: r231383 - in head: lib/libutil usr.sbin/vipw Message-ID: <20120211041345.Q3573@besplex.bde.org> In-Reply-To: <CAE-mSOJ5928krC_4sSW5cec%2B6JLKD8BRoKvZCuc8xEzY4qrvaA@mail.gmail.com> References: <201202101340.q1ADeWDj076596@svn.freebsd.org> <CAE-mSOJ5928krC_4sSW5cec%2B6JLKD8BRoKvZCuc8xEzY4qrvaA@mail.gmail.com>
next in thread | previous in thread | raw e-mail | index | archive | help
This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --0-267995700-1328894422=:3573 Content-Type: TEXT/PLAIN; charset=X-UNKNOWN; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE On Fri, 10 Feb 2012, Sergey Kandaurov wrote: > On 10 February 2012 17:40, Ed Schouten <ed@freebsd.org> wrote: >> Log: >> =A0Detect file modification properly by using tv_nsec. >> >> =A0POSIX 2008 standardizes st_mtim, meaning we can simply use nanosecond >> =A0precision to detect file modification. > > I am not sure we can use subsecond precision there with currently set > sysctl vfs.timestamp_precision=3D0. Also, not all file systems support even seconds precision. So the deleted BUGS section applies irrespective of vfs.timestamp_precision, except it doesn't describe the full extent of the problem. Sleeping for just 1 second is not enough if the timestamp precision is large. The BUGS section also applies respective of vfs.timestamp_precision, when the user uses the supported setting vfs.timestamp_precision=3D0. Of course, important databases that need POSIX semantics shouldn't be put on file systems without POSIX times, but you need a BUGS section somewhere to tell you not to do that. Bruce --0-267995700-1328894422=:3573--
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20120211041345.Q3573>