Re: 2.6.35 Regression: Ages spent discarding blocks that weren't used!

From: Martin K. Petersen
Date: Wed Aug 04 2010 - 14:03:11 EST


>>>>> "Mark" == Mark Lord <kernel@xxxxxxxxxxxx> writes:

Mark> Looks to me like more and more things are using the block discard
Mark> functionality, and as predicted it is slowing things down
Mark> enormously.

Mark> The problem is that we still only discard tiny bits (a single
Mark> range still??) per TRIM command, rather than batching larger
Mark> ranges and larger numbers of ranges into single TRIM commands.

Mark> That's a very poor implementation, especially when things start
Mark> enabling it by default. Eg. the swap code, mke2fs, etc..

I'm working on aggregation. But it's harder than we initially
thought...

--
Martin K. Petersen Oracle Linux Engineering
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