linux-kernel - Re: Extremely slow IO with a PCMCIA CompactFlash adapter

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Sun, 2 Aug 2009 11:58:26 +0100
From:	Alan Cox <alan@...rguk.ukuu.org.uk>
To:	Jack Byer <ojbyer@....net>
Cc:	Robert Hancock <hancockrwd@...il.com>,
	Andreas Mohr <andi@...as.de>, linux-kernel@...r.kernel.org
Subject: Re: Extremely slow IO with a PCMCIA CompactFlash adapter

> irq 3: nobody cared (try booting with the "irqpoll" option)
> Pid: 23488, comm: modprobe Not tainted 2.6.31-rc4 #2
> Call Trace:

Something is misrouting interrupts on your machine. COuld be an ACPI bug,
could be wrong tables in the BIOS etc.

> Now I rebooted with irqpoll and everything looks good in dmesg:

It will recover from the problem sort of

> Now my transfer rate has increased to 20 kilobyte / second read, about
> 4 times faster than before but still pretty slow.

You should see nearer 200K/sec (PIO 0) but if the device IRQ is being
lost due to misrouting then the device is being polled off the timer tick
and that will drastically reduce performance.

So its a firmware/acpi/irq sort of problem not an IDE one. Try running
with acpi=off and without irqpoll just as a test.

Alan
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/