Re: [Linux-ia64] [PATCH] Performance Patch for TLB misses

David Mosberger
2002-11-11T18:48:27Z

>>>>> On Mon, 11 Nov 2002 09:49:49 +0100, Christian Hildner <christian.hildner@hob.de> said:

Christian> Yes, but for the kernel it is allowed also without the
Christian> patch and the the user could insert a duplicate mapping
Christian> for the same physical page but this useless for him
Christian> because of the access rights and also the kernel would
Christian> not use these pages (because the kernel has no knowledge
Christian> of this pages).

Useless to the user, but dangerous to the health of the machine!
Please note that attribute aliasing can lead to a machine-check and
therefore is an absolute no-no (the machine check could be triggered
either by a hardware-prefetch or due to speculative memory accesses
inside the kernel).

--david