Subject: Re: changing default for UFS_DIRHASH and NEW_BUFQ_STRATEGY
To: None <>
From: SODA Noriyuki <>
List: tech-kern
Date: 06/09/2005 00:52:43
>>>>> On Wed, 8 Jun 2005 11:25:13 -0400,
	Thor Lancelot Simon <> said:

> If SGI's claims can be believed, BUFQ_PRIOCSCAN should do better both
> on clients and servers than either the traditional sorting (which is
> pretty much CSCAN) or pure read priority.

Well, at the NetBSD BOF of Japan NetBSD users' group in last year,
I've heard from Yamamoto-san (who actually implemented PRIOCSCAN as
you know) that PRIOCSCAN is still not good enough as expected, because
currently UVM doesn't distinguish busy-but-valid pages (for writing)
from busy-and-invalid pages (for reading).

This issue was already reported by him in the year before last: