Re: msync() behaviour broken for MS_ASYNC, revert patch?

From: Nick Piggin
Date: Thu Feb 09 2006 - 03:35:48 EST


Andrew Morton wrote:


2.4:

MS_ASYNC: dirty the pagecache pages, start I/O
MS_SYNC: dirty the pagecache pages, start I/O, wait on I/O

2.6:

MS_ASYNC: dirty the pagecache pages
MS_SYNC: dirty the pagecache pages, start I/O, wait on I/O.

So you're saying that doing the I/O in that 25-100msec window allowed your
app to do more pipelining.

I think for most scenarios, what we have in 2.6 is better: it gives the app
more control over when the I/O should be started.

How so?

--
SUSE Labs, Novell Inc.
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