Messages in this thread | | | Subject | Re: Noatime vs relatime | From | Xavier Bestel <> | Date | Fri, 10 Aug 2007 16:44:35 +0200 |
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On Fri, 2007-08-10 at 07:26 -0700, Vlad wrote: > Relatime seems to be wasteful of both IO resources _and_ CPU cycles. > Instead of performing a single IO operation (as atime does), relatime > performs at least three IO operations and three CPU-dependent > operations: > > 1) a read IO operation to find out the old atime > 2) a read IO operation to find out the old ctime > 3) a read IO operation to find out the old mtime > 4) Comparison of "old atime is <= than mtime/ctime" > 5) Find out current time > 6) Comparison of "current time minus old atime is > X"
As all [acm]times are stored in the same block (inode), I bet all this is one single IO, plus some insignificant computation (3 comparisons plus reading time is really smaller than one block IO).
Xav
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