From: "Linh Dang" <linhd@nortelnetworks.com>
To: David Woodhouse <dwmw2@infradead.org>
Cc: linux-mtd@lists.infradead.org
Subject: Hi Latency in do_read_onechip (was Re: Bottom halves being disabled)
Date: Thu, 09 Sep 2004 14:12:19 -0400 [thread overview]
Message-ID: <wn5brgfia64.fsf_-_@linhd-2.ca.nortel.com> (raw)
In-Reply-To: <1093431210.3777.1535.camel@imladris.demon.co.uk> (David Woodhouse's message of "Wed, 25 Aug 2004 11:53:30 +0100")
Hi David,
On our system, we have some slow AMD nor flash. The line
map_copy_from(map, buf, adr, len);
in do_read_onechip (in cfi_cmdset_0002.c) is called while holding a
spin_lock (chip->mutex). This triggers 450usec non-preemptible periods
on our system.
1. Is there any plan to fix this?
2. Is it safe to replace the spin_lock with a semaphore?
3. while mtd has to lock softirq?
Thanx
--
Linh Dang
next prev parent reply other threads:[~2004-09-09 18:12 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-08-24 12:09 Bottom halves being disabled Ed Co
2004-08-24 12:24 ` David Woodhouse
2004-08-25 2:36 ` Linh Dang
2004-08-25 9:38 ` David Woodhouse
2004-08-25 10:48 ` Linh Dang
2004-08-25 10:53 ` David Woodhouse
2004-08-25 12:46 ` Linh Dang
2004-09-09 18:12 ` Linh Dang [this message]
2004-08-24 12:28 ` Josh Boyer
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