Re: [PATCH] mm: remove global locks from mm/highmem.c
From: Andrew Morton <hidden>
Date: 2007-01-30 01:41:45
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On Mon, 29 Jan 2007 17:31:20 -0800 "Martin J. Bligh" [off-list ref] wrote:
Peter Zijlstra wrote:quoted
On Sun, 2007-01-28 at 14:29 -0800, Andrew Morton wrote:quoted
As Christoph says, it's very much preferred that code be migrated over to kmap_atomic(). Partly because kmap() is deadlockable in situations where a large number of threads are trying to take two kmaps at the same time and we run out. This happened in the past, but incidences have gone away, probably because of kmap->kmap_atomic conversions.quoted
From which callsite have you measured problems?CONFIG_HIGHPTE code in -rt was horrid. I'll do some measurements on mainline.CONFIG_HIGHPTE is always horrid -we've known that for years.
We have? What's wrong with it? <looks around for bug reports>
Don't use it. If that's all we're fixing here, I'd be highly suspect ...
highpte uses atomic kmaps - it is unrelated to this work. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>