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Re: [Xen-devel] swiotlb

To: Ky Srinivasan <ksrinivasan@xxxxxxxxxx>
Subject: Re: [Xen-devel] swiotlb
From: Don Dutile <ddutile@xxxxxxxxxx>
Date: Thu, 13 Apr 2006 21:51:28 -0400
Cc: xen-devel@xxxxxxxxxxxxxxxxxxx, Don Dutile <ddutile@xxxxxxxxxx>
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Ky,
You are correct. I received this as a bugzilla on FC-5. Testing a solution now (replacing copy_to_user w/copy_to_user_inatomic). The other problem with the call to copy_to_user is that a kmap_atomic() is done just before it as well, and the thread can't be blocked before the kunmap_atomic() is invoked (after the copy_to_user()).

Unfortunately, tomorrow is company holiday, so I won't complete the testing until Monday; need to get more memory to force swiotlb's sync_single() to do the copy (due to bounce IO).

- Don


Ky Srinivasan wrote:
Given that the function __sync_single() can be called in an interrupt
context, why do we call a   potentially blocking function
(__copy_to_user) from within this function?

Regards,

K. Y


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