Date: 24 Jun 1997 08:52:37 GMT From: nnd@itfs.nsk.su To: smp@freebsd.org Subject: Re: SMP_PRIVPAGES Message-ID: <5oo1sl$mdv@news.itfs.nsk.su> References: <199706232018.OAA07315@Ilsa.StevesCafe.com>
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Steve Passe <smp@csn.net> wrote:
> Peter has committed the code for enabling SMP_PRIVPAGES. Not that it
> is automatic, ie you don't need to add the option to your config file.
> I successfully used it to "make world" with -current as of earlier this
> morning.
> Thanx, Peter!
I also make world and make kernel with this
code and after that discover that famous 'dd if=/dev/zero of=/dev/null...'
bencmark shows even smaller results than previous SMP-kernel.
After that I've decide to try the next patch on
/sys/i386/isa/npx.c:
--- npx.c Tue Jun 24 14:42:03 1997
+++ npx.c.orig Tue Jun 24 09:02:56 1997
@@ -413,7 +413,7 @@
}
npxinit(__INITIAL_NPXCW__);
-#if defined(I586_CPU)
+#if defined(I586_CPU) && !defined(SMP)
/* FPU not working under SMP yet */
if (cpu_class == CPUCLASS_586 && npx_ex16) {
if (!(dvp->id_flags & NPX_DISABLE_I586_OPTIMIZED_BCOPY)) {
and ... this is a result:
(before my patch)
dd if=/dev/zero of=/dev/null bs=1m count=1000
1000+0 records in
1000+0 records out
1048576000 bytes transferred in 21.219967 secs (49414591 bytes/sec)
(and after it)
dd if=/dev/zero of=/dev/null bs=1m count=1000
1000+0 records in
1000+0 records out
1048576000 bytes transferred in 11.985571 secs (87486529 bytes/sec)
The last number is still lose to NON-SMP case, but it seems
to me that there is another place to gain speed for bzero/bcopy -
in file /sys/i386/i386/support.s there is a "label" kernel_fpu_lock:
As I can (NOT?) understand it can be duplicated for each CPU
and may be this can give us some more speedup of bzero/bcopy ?
N.Dudorov
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