Re: io_submit() taking a long time to return ?

From: Zach Brown
Date: Thu Jul 13 2006 - 12:47:13 EST



> what do u means by "sync block mapping " ?

To find out what blocks to issue async IO against the submission path
reads metadata from the file system that maps file regions to disk
blocks. These metadata reads are synchronous and so can block the
submitting task. The mappings tend to be cached, though, which is why
this doesn't seem to be a problem in practice.

- z
-
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