Re: Happy New Year PARISC

[John David Anglin <dave.anglin@bell.net>]

On 1/3/2012 6:50 AM, Carlos O'Donell wrote:
> On Mon, Jan 2, 2012 at 6:12 PM, John David Anglin<dave.anglin@bell.net>  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