From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nick Piggin Date: Tue, 01 May 2007 11:52:50 +0000 Subject: Re: Fw: [PATCH] ia64: race flushing icache in do_no_page path Message-Id: <46372A12.9080802@yahoo.com.au> List-Id: References: <200704281817.l3SIHu0P001764@smtp.corp.google.com> In-Reply-To: <200704281817.l3SIHu0P001764@smtp.corp.google.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Rohit Seth Cc: 'Hugh Dickins' , 'Mike Stroyan' , 'Andrew Morton' , "'Luck, Tony'" , linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org Rohit Seth wrote: >>and >>it's only interested when it's executable i.e. "lazy_mmu_prot_update" >>is a name concealing some overdesign. > > > You are right that ia64 is only interested in whne the execute permissions > kick in (and FWIW ia64 used to use update_mmu_cache API to do what it is now > doing lazy_mmu_prot_update). Though the idea was to design an API that any > arch can use to know when ever there is change in protections on a mapping. What I think what we should do is audit flush_icache_page coverage, and convert ia64 to use that (because it needs this to happen _before_ the pte is set). All we should need to do is add a pte argument to flush_icache, and it should be possible to do what ia64 wants, and we can remove lazy_mmu_prot_update (or at least rename it to something like flush_icache_page_chprot and move it to the normal flush_icache_page position above set_pte if not all architectures want their flush_icache_page called at protection change time). -- SUSE Labs, Novell Inc.