Date: Thu, 15 Dec 2005 19:33:53 +0200
From: "Michael S. Tsirkin" <mst@mellanox.co.il>
To: linux-kernel@vger.kernel.org
Subject: kmap_atomic slot collision
Message-ID: <20051215173353.GA29402@mellanox.co.il>
Reply-To: "Michael S. Tsirkin" <mst@mellanox.co.il>
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Hi!
I'm trying to use kmap_atomic from both interrupt and task context.
My idea was to do local_irq_save and then use KM_IRQ0/KM_IRQ1:
since I'm disabling interrupts I assumed that this should be safe.
The relevant code is here:
https://openib.org/svn/gen2/trunk/src/linux-kernel/infiniband/ulp/sdp/sdp_iocb.c

However, under stress I see errors from arch/i386/mm/highmem.c:42
        if (!pte_none(*(kmap_pte-idx)))
                BUG();

Apparently, my routine, running from a task context, races with
some other kernel code, and so I'm trying to use a slot that was not
yet unmapped.

Anyone has an idea on what I could be doing wrong?

Thanks,
-- 
MST
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