lkml.org 
[lkml]   [2006]   [Aug]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH rev2 1/4] dmaengine: enable mutliple clients and operations
From

Can I ask that the known bugs in the I/O AT DMA code be fixed
before we start adding new features to it?

Specifically, the lock_cpu_hotplug() call in net_dma_rebalance()
is still there and being invoked with a spinlock held. The
spinlock is grabbed by the caller, netdev_dma_event() which
grabs the net_dma_event_lock spinlock.

You cannot invoke lock_cpu_hotplug() while holding a spinlock
because lock_cpu_hotplug(), as seen in kernel/cpu.c, takes
a semaphore which can sleep. Sleeping while holding a spinlock
is not allowed.

This is the second time I have tried to make the Intel developers
aware of this bug. So please fix this problem.

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

\
 
 \ /
  Last update: 2006-08-01 08:15    [W:0.828 / U:0.068 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site