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Subject: Re: ZFS txg implementation flaw
From: Jordan Hubbard <jkh@ixsystems.com>
In-Reply-To: <20131028092844.GA24997@zxy.spb.ru>
Date: Mon, 28 Oct 2013 14:22:16 -0700
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References: <20131028092844.GA24997@zxy.spb.ru>
To: Slawa Olhovchenkov <slw@zxy.spb.ru>
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On Oct 28, 2013, at 2:28 AM, Slawa Olhovchenkov <slw@zxy.spb.ru> wrote:

> As I see ZFS cretate seperate thread for earch txg writing.
> Also for writing to L2ARC.
> As result -- up to several thousands threads created and destoyed per
> second. And hundreds thousands page allocations, zeroing, maping
> unmaping and freeing per seconds. Very high overhead.

How are you measuring the number of threads being created / destroyed?   =
This claim seems erroneous given how the ZFS thread pool mechanism =
actually works (and yes, there are thread pools already).

It would be helpful to both see your measurement methodology and the =
workload you are using in your tests.

- Jordan