Date: Sun, 15 Jan 2006 00:30:57 +0800 From: Huang wen hui <hwh@gddsn.org.cn> To: java@freebsd.org Subject: Performance patch for jdk1.5.0/amd64 Message-ID: <43C92741.7000803@gddsn.org.cn>
next in thread | raw e-mail | index | archive | help
hi,
I recently notice that jdk1.5.0-p2/amd64 is slower than jdk1.5.0-p2/i386
on the same hardware in some situation.
In my test case is 15115 ms vs 3779 ms. using -Xprof option show that
some methods(specially using a lot of cpu time) are
run as interpreted mode on amd64, and are run as compiled code on i386.
The following patch seems to solve this problem.
I am not totally understand this patch. just back port from jdk16. but
this patch really speed up jdk.
Patched jdk1.5.0 test result:
wfdb2# ~hwh/j2sdk-image/bin/java -Xmx256m -jar TestDatabaseEvtData.jar
"2006-01-14 00:00:00" "2006-01-14 00:30:00"
Use DatabaseEvtData.properties as log4j configuration
INFO [main] (DatabaseEvtData.java:501) - DECODE MiniSeed elapse time:
3993 ms.
orig jdk1.5.0 test result:
wfdb2# ~hwh/j2sdk-image.orig/bin/java -Xmx256m -jar
TestDatabaseEvtData.jar "2006-01-14 00:00:00" "2006-01-14 00:30:00"
Use DatabaseEvtData.properties as log4j configuration
INFO [main] (DatabaseEvtData.java:501) - DECODE MiniSeed elapse time:
16141 ms.
# cat amd64.ad.patch
--- ../../hotspot/src/cpu/amd64/vm/amd64.ad.orig Sat Jan 14 20:06:02 2006
+++ ../../hotspot/src/cpu/amd64/vm/amd64.ad Sat Jan 14 20:05:37 2006
@@ -6095,6 +6095,18 @@
ins_pipe(pipe_slow); // XXX
%}
+instruct prefetcht0(memory mem)
+%{
+ match(Prefetch mem);
+ predicate(!VM_Version::has_prefetchw());
+ ins_cost(125);
+
+ format %{ "prefetcht0 $mem\t# prefetch into L1" %}
+ opcode(0x0F, 0x18); /* Opcode 0F 18 /1 */
+ ins_encode(REX_mem(mem), OpcP, OpcS, RM_opc_mem(0x01, mem));
+ ins_pipe(pipe_slow);
+%}
+
instruct prefetch(memory mem)
%{
match(Prefetch mem);
# cat prefetch_bsd_amd64.inline.hpp.patch
---
../../hotspot/src/os_cpu/bsd_amd64/vm/prefetch_bsd_amd64.inline.hpp.orig
Sat Jan 14 23:51:41 2006
+++ ../../hotspot/src/os_cpu/bsd_amd64/vm/prefetch_bsd_amd64.inline.hpp
Sat Jan 14 23:52:54 2006
@@ -6,24 +6,14 @@
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/
-inline void Prefetch::read(void* loc, intx interval)
+inline void Prefetch::read(void* loc, intx interval)
{
- __builtin_prefetch((char*) loc + interval, 0); // prefetcht0 (%rsi,
%rdi,1)
+ __asm__ ("prefetcht0 (%0,%1,1)" : : "r" (loc), "r" (interval));
}
inline void Prefetch::write(void* loc, intx interval)
{
- // Force prefetchw. The gcc builtin produces prefetcht0 or prefetchw
- // depending on command line switches we don't control here.
- // Use of this method should be gated by VM_Version::has_prefetchw.
- /*
- * How do we invoke VM_Version::has_prefetchw here?
- * Can we do something at compile time instead to remove that overhead?
- */
-//#ifdef __amd64__
-// __asm__ ("prefetchw (%0,%1,1)" : : "r" (loc), "r" (interval));
-//#elif __em64t__
+ // Do not use the 3dnow prefetchw instruction. It isn't supported on
em64t.
+ // __asm__ ("prefetchw (%0,%1,1)" : : "r" (loc), "r" (interval));
__asm__ ("prefetcht0 (%0,%1,1)" : : "r" (loc), "r" (interval));
-//#endif
- // __builtin_prefetch((char*) loc + interval, 1); //
prefetcht0/prefetchw (%rsi,%rdi,1)
}
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?43C92741.7000803>