From: John Sigler <linux.kernel@free.fr>
To: Ingo Molnar <mingo@elte.hu>
Cc: linux-rt-users@vger.kernel.org,
oprofile-list@lists.sourceforge.net,
linux-kernel@vger.kernel.org
Subject: Re: Pin-pointing the root of unusual application latencies
Date: Tue, 24 Jul 2007 11:20:33 +0200 [thread overview]
Message-ID: <46A5C461.7030806@free.fr> (raw)
In-Reply-To: <46A5B8E3.4060004@free.fr>
John Sigler wrote:
> ( check_dektec_in-1095 |#0): new 271 us user-latency.
> ( check_dektec_in-1095 |#0): new 275 us user-latency.
> ( check_dektec_in-1095 |#0): new 290 us user-latency.
> ( check_dektec_in-1095 |#0): new 297 us user-latency.
> ( check_dektec_in-1095 |#0): new 345 us user-latency.
> ( check_dektec_in-1095 |#0): new 358 us user-latency.
> ( check_dektec_in-1095 |#0): new 384 us user-latency.
> ( check_dektec_in-1095 |#0): new 392 us user-latency.
> ( check_dektec_in-1095 |#0): new 395 us user-latency.
> ( check_dektec_in-1095 |#0): new 396 us user-latency.
> ( check_dektec_in-1095 |#0): new 1031 us user-latency.
> ( check_dektec_in-1095 |#0): new 1100 us user-latency.
> ( check_dektec_in-1095 |#0): new 1105 us user-latency.
> ( check_dektec_in-1095 |#0): new 1106 us user-latency.
>
> Here's the function trace for the 1106-µs latency:
>
> http://linux.kernel.free.fr/latency/1106-us-trace.txt
The function trace for 400-µs latencies is different:
( check_dektec_in-1145 |#0): new 275 us user-latency.
( check_dektec_in-1145 |#0): new 276 us user-latency.
( check_dektec_in-1145 |#0): new 288 us user-latency.
( check_dektec_in-1145 |#0): new 289 us user-latency.
( check_dektec_in-1145 |#0): new 289 us user-latency.
( check_dektec_in-1145 |#0): new 290 us user-latency.
( check_dektec_in-1145 |#0): new 297 us user-latency.
( check_dektec_in-1145 |#0): new 345 us user-latency.
( check_dektec_in-1145 |#0): new 354 us user-latency.
( check_dektec_in-1145 |#0): new 377 us user-latency.
( check_dektec_in-1145 |#0): new 393 us user-latency.
http://linux.kernel.free.fr/latency/393-us-trace.txt
There are ~200 calls to ioread32 from mdio_read from speedo_timer.
http://lxr.linux.no/source/drivers/net/eepro100.c#L1159
http://lxr.linux.no/source/drivers/net/eepro100.c#L928
In this case, and as far as I understand, the culprit is the eepro100
driver talking to one of the NICs (which one?). Is that correct?
What is the consequence of IRQ10 being shared by eth2 and
by my I/O board?
How can I force Linux to assign different IRQs to every peripheral
if I have free IRQs lines?
Regards.
next prev parent reply other threads:[~2007-07-24 9:20 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <469600F7.3060603@free.fr>
2007-07-23 9:53 ` Pin-pointing the root of unusual application latencies Ingo Molnar
2007-07-23 14:14 ` John Sigler
2007-07-23 16:04 ` Ingo Molnar
2007-07-23 16:44 ` John Sigler
2007-07-24 8:31 ` John Sigler
2007-07-24 9:20 ` John Sigler [this message]
2007-07-25 13:04 ` John Sigler
2007-07-25 13:05 ` Ingo Molnar
2007-07-25 13:20 ` John Sigler
2007-07-25 13:38 ` Ingo Molnar
2007-07-25 14:05 ` John Sigler
2007-07-25 15:28 ` Karsten Wiese
2007-07-25 15:46 ` John Sigler
2007-07-25 16:31 ` Karsten Wiese
2007-07-25 17:09 ` Len Brown
2007-07-26 8:35 ` John Sigler
2007-07-26 10:45 ` John Sigler
2007-07-26 12:02 ` John Sigler
2007-07-26 15:16 ` John Sigler
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