Vectorized Read?

Vectorized Read?

Posted Mar 23, 2007 21:34 UTC (Fri) by giraffedata (subscriber, #1954)
In reply to: Vectorized Read? by vmole
Parent article: The 2007 Linux Storage and File Systems Workshop

... and you can read at specific offsets (which is what readv(2) gives you), isn't that being able to read specific blocks?

You need to be able to read not just specific offsets, but specific discontiguous offsets. readv() does not give you that. You have to read a contiguous area of the file (block device). You cannot make it read from 4K to 8K and 12K to 16K.

What readv() adds to read() is that you can read that contiguous file region into discontiguous memory, whereas with read() it has to go into a single contiguous range of memory addresses.

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