From mboxrd@z Thu Jan 1 00:00:00 1970 From: John David Anglin Subject: Re: Happy New Year PARISC Date: Tue, 03 Jan 2012 10:13:30 -0500 Message-ID: <4F031B1A.4010908@bell.net> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Cc: Grant Grundler , linux-parisc List To: Carlos O'Donell Return-path: In-Reply-To: List-ID: List-Id: linux-parisc.vger.kernel.org On 1/3/2012 6:50 AM, Carlos O'Donell wrote: > On Mon, Jan 2, 2012 at 6:12 PM, John David Anglin wrote: >> None of this worked. Attached patch as it stands. Comments and testing >> appreciated. > Could you clarify what you mean by "none of this worked?" > I tried eliminating the flushes that occur in kunmap_atomic on PA8800 and PA8900 after the calls to clear_user_page and copy_user_page by defining clear_user_highpage and copy_user_highpage. I had thought the flushes weren't necessary. There's something about this that I don't understand. Why do we need to flush non-equivalent page mappings that aren't used? Also tried: #define flush_cache_dup_mm(mm) do { } while (0) In both cases, init died causing a panic at boot. Maybe there's something missing at startup. Most arch's have the above define for flush_cache_dup_mm. Our define really hurts fork performance. The GCC testsuite takes almost twice as long to run on linux as hpux. On the other hand, build times are fairly comparable. Dave -- John David Anglin dave.anglin@bell.net