From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: pte_offset_map for ppc assumes HIGHPTE From: Benjamin Herrenschmidt In-Reply-To: References: Content-Type: text/plain Date: Thu, 26 Jul 2007 09:22:45 +1000 Message-Id: <1185405765.5439.371.camel@localhost.localdomain> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Andreas Schwab Cc: Satya , linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: On Thu, 2007-07-26 at 01:18 +0200, Andreas Schwab wrote: > Satya writes: > > > hello, > > The implementation of pte_offset_map() for ppc assumes that PTEs are > > kept in highmem (CONFIG_HIGHPTE). There is only one implmentation of > > pte_offset_map() as follows (include/asm-ppc/pgtable.h): > > > > #define pte_offset_map(dir, addr) \ > > ((pte_t *) kmap_atomic(pmd_page(*(dir)), KM_PTE0) + pte_index(addr)) > > > > Shouldn't this be made conditional according to CONFIG_HIGHPTE is > > defined or not > > kmap_atomic is always defined with or without CONFIG_HIGHPTE. > > > (as implemented in include/asm-i386/pgtable.h) ? > > I don't think that needs it either. Depends... if you have CONFIG_HIGHMEM and not CONFIG_HIGHPTE, you are wasting time going through kmap_atomic unnecessarily no ? it will probably not do anything because the PTE page is in lowmem but still... Ben. -- 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: email@kvack.org