From: Al Boldi <a1426z@gawab.com>
To: Denis Vlasenko <vda@ilport.com.ua>
Cc: Willy Tarreau <willy@w.ods.org>, linux-kernel@vger.kernel.org
Subject: Re: Eradic disk access during reads
Date: Sun, 18 Sep 2005 16:40:19 +0300 [thread overview]
Message-ID: <200509181640.19984.a1426z@gawab.com> (raw)
In-Reply-To: <200509181400.27004.vda@ilport.com.ua>
Denis Vlasenko wrote:
> On Saturday 17 September 2005 19:38, Al Boldi wrote:
> > > # dd if=/dev/hda of=/dev/null bs=16M
> > 2.4.31 # nmeter t6 c x i b d100
> > 18:56:36.009981 cpu [SSSSSSSS..] ctx 145 int 86 bio 4.7M 0
> > 18:56:36.110327 cpu [SSSSSSSS..] ctx 145 int 87 bio 4.8M 0
> > 18:56:36.210735 cpu [SSSSSSSS..] ctx 139 int 88 bio 4.7M 0
> > 18:56:36.310315 cpu [SSSSSSSS..] ctx 142 int 85 bio 4.7M 0
> >
> > 2.6.13 # nmeter t6 c x i b d100
> > 18:09:22.117959 cpu [SSSSSSSSSD] ctx 80 int 47 bio 4.7M 0
> > 18:09:22.217932 cpu [SSSSSSDDDD] ctx 83 int 48 bio 4.8M 0
> > 18:09:22.319200 cpu [SSSSDDDDDI] ctx 81 int 56 bio 4.7M 28k
> > 18:09:22.407979 cpu [SSSSSSSSSD] ctx 60 int 38 bio 3.8M 0
> > 18:09:22.517960 cpu [SSSSSSSSDI] ctx 95 int 61 bio 5.2M 52k
>
> Well, I do not see any bursts you mention...
Can you try 2.4.31?
> Anyway, my data:
> 13:52:09.201450 cpu [SSSSSSDDII] ctx 34 int 142 bio 4.1M 0
> 13:52:09.301176 cpu [SSSSSSSDDI] ctx 39 int 138 bio 3.8M 0
> 13:52:09.401806 cpu [SSSSSSSSDI] ctx 55 int 157 bio 4.3M 0
> 13:52:09.501077 cpu [SSSSDDDDDI] ctx 32 int 121 bio 2.2M 0
> 13:52:09.601067 cpu [SSSDDDDDDD] ctx 24 int 127 bio 1.7M 0
> 13:52:09.701108 cpu [SSSSSSSDDI] ctx 50 int 153 bio 4.1M 0
> 13:52:09.802156 cpu [SSSSDDDDII] ctx 34 int 139 bio 2.7M 0
> 13:52:09.902026 cpu [SSSSSSSSDD] ctx 44 int 152 bio 4.0M 0
> 13:52:10.002041 cpu [SSSSDDDDDI] ctx 39 int 126 bio 2.2M 0
> 13:52:10.100997 cpu [SSSSDDDDDI] ctx 46 int 129 bio 2.7M 0
> 13:52:10.201964 cpu [SSSSSSSDDI] ctx 57 int 139 bio 3.6M 0
> 13:52:10.303468 cpu [SSSSDDDDDI] ctx 34 int 133 bio 2.2M 0
> 13:52:10.401523 cpu [SSSSSSSDDI] ctx 50 int 145 bio 3.6M 4096
> 13:52:10.500934 cpu [SSSSSSSSII] ctx 66 int 139 bio 4.1M 0
Does not look smooth.
> /dev/hda:
> UDMA modes: udma0 udma1 udma2 udma3 udma4 *udma5
same here.
> My CPU is not that new:
PII - 400Mhz here.
> hdc (an old disk):
> 13:52:40.201718 cpu [SSSDDDDDDD] ctx 26 int 112 bio 1.2M 0
> 13:52:40.301569 cpu [SSDDDDDDDD] ctx 28 int 109 bio 1.2M 0
> 13:52:40.402552 cpu [SSDDDDDDDI] ctx 23 int 111 bio 1.2M 0
> 13:52:40.502535 cpu [SSDDDDDDDD] ctx 22 int 110 bio 1.2M 0
> 13:52:40.601507 cpu [SSDDDDDDDI] ctx 26 int 111 bio 1.2M 0
> 13:52:40.701493 cpu [SSDDDDDDDD] ctx 23 int 110 bio 1.2M 0
Looks smooth.
Also, great meter! Best of all does not hog the CPU!
Could you add a top3 procs display?
Thanks!
--
Al
next prev parent reply other threads:[~2005-09-18 13:43 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-09-17 4:26 Al Boldi
2005-09-17 5:50 ` Willy Tarreau
2005-09-17 10:32 ` Al Boldi
2005-09-17 10:44 ` Denis Vlasenko
2005-09-17 16:38 ` Al Boldi
2005-09-18 11:00 ` Denis Vlasenko
2005-09-18 13:40 ` Al Boldi [this message]
2005-09-18 16:02 ` Denis Vlasenko
2005-09-18 16:34 ` Willy Tarreau
2005-09-18 18:08 ` Al Boldi
2005-09-17 18:46 ` Willy Tarreau
2005-09-18 4:16 ` Al Boldi
2005-09-18 5:23 ` Willy Tarreau
2005-09-18 6:54 ` Al Boldi
2005-09-18 10:40 ` Denis Vlasenko
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