Date: Wed, 11 Jan 2006 17:05:02 -0800
From: William Lee Irwin III <wli@holomorphy.com>
To: "Chen, Kenneth W" <kenneth.w.chen@intel.com>
Cc: "'Adam Litke'" <agl@us.ibm.com>, linux-kernel@vger.kernel.org,
       linux-mm@kvack.org
Subject: Re: [PATCH 2/2] hugetlb: synchronize alloc with page cache insert
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On Wed, Jan 11, 2006 at 04:40:37PM -0800, Chen, Kenneth W wrote:
> What if two processes fault on the same page and races with find_lock_page(),
> both find page not in the page cache.  The process won the race proceed to
> allocate last hugetlb page.  While the other will exit with SIGBUS.
> In theory, both processes should be OK.

This is supposed to fix the incarnation of that as a preexisting
problem, but you're right, there is no fallback or retry for the case
of hugepage queue exhaustion. For some reason I saw a phantom page
allocator fallback in the hugepage allocator changes.

Looks like back to the drawing board for this pair of patches, though
I'd be more than happy to get a solution to this.


-- wli
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