From mboxrd@z Thu Jan 1 00:00:00 1970
From: bugme-daemon@bugzilla.kernel.org
Subject: [Bug 10846] Slow write on LSISAS1068E (SAS6/iR) on kernel >= 2.6.22
Date: Wed, 4 Jun 2008 08:22:42 -0700 (PDT)
Message-ID: <20080604152242.3333E10805E@picon.linux-foundation.org>
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http://bugzilla.kernel.org/show_bug.cgi?id=10846
------- Comment #8 from dom.lalot@gmail.com 2008-06-04 08:22 -------
Well,
I don't know what to say as a conclusion. We checked on another machine (sata
devices). We confirmed the difference between the kernels.
I don't know the algorythum about the write caching, in fact we have seen a
difference. If we stay under 80Mo, we stay in cache without effect from the
write back or write through written in dmesg. 2.6.21 and above are OK.
It you test for 600Mo, you get hardware speed on 2.6.22+
As a conclusion: I was not lucky in doing such a test on a new hardware. I
believed it comes from SAS and finaly that's more a change in Memory
Management. By the way, if somebody can tell me where we can tune the max
memory cache in kernel, that would be great. Anyway, for our purpose, it's not
usefull.
Thanks
Dominique
Can you close the bug, or should I?
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