Mercurial > hg > truffle
view src/os_cpu/bsd_x86/vm/thread_bsd_x86.cpp @ 20543:e7d0505c8a30
8059758: Footprint regressions with JDK-8038423
Summary: Changes in JDK-8038423 always initialize (zero out) virtual memory used for auxiliary data structures. This causes a footprint regression for G1 in startup benchmarks. This is because they do not touch that memory at all, so the operating system does not actually commit these pages. The fix is to, if the initialization value of the data structures matches the default value of just committed memory (=0), do not do anything.
Reviewed-by: jwilhelm, brutisso
author | tschatzl |
---|---|
date | Fri, 10 Oct 2014 15:51:58 +0200 |
parents | f2110083203d |
children | 774e1c2f8741 |
line wrap: on
line source
/* * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #include "precompiled.hpp" #include "runtime/frame.inline.hpp" #include "runtime/thread.inline.hpp" // For Forte Analyzer AsyncGetCallTrace profiling support - thread is // currently interrupted by SIGPROF bool JavaThread::pd_get_top_frame_for_signal_handler(frame* fr_addr, void* ucontext, bool isInJava) { assert(Thread::current() == this, "caller must be current thread"); return pd_get_top_frame(fr_addr, ucontext, isInJava); } bool JavaThread::pd_get_top_frame_for_profiling(frame* fr_addr, void* ucontext, bool isInJava) { return pd_get_top_frame(fr_addr, ucontext, isInJava); } bool JavaThread::pd_get_top_frame(frame* fr_addr, void* ucontext, bool isInJava) { assert(this->is_Java_thread(), "must be JavaThread"); JavaThread* jt = (JavaThread *)this; // If we have a last_Java_frame, then we should use it even if // isInJava == true. It should be more reliable than ucontext info. if (jt->has_last_Java_frame()) { *fr_addr = jt->pd_last_frame(); return true; } // At this point, we don't have a last_Java_frame, so // we try to glean some information out of the ucontext // if we were running Java code when SIGPROF came in. if (isInJava) { ucontext_t* uc = (ucontext_t*) ucontext; intptr_t* ret_fp; intptr_t* ret_sp; ExtendedPC addr = os::Bsd::fetch_frame_from_ucontext(this, uc, &ret_sp, &ret_fp); if (addr.pc() == NULL || ret_sp == NULL ) { // ucontext wasn't useful return false; } frame ret_frame(ret_sp, ret_fp, addr.pc()); if (!ret_frame.safe_for_sender(jt)) { #ifdef COMPILER2 // C2 uses ebp as a general register see if NULL fp helps frame ret_frame2(ret_sp, NULL, addr.pc()); if (!ret_frame2.safe_for_sender(jt)) { // nothing else to try if the frame isn't good return false; } ret_frame = ret_frame2; #else // nothing else to try if the frame isn't good return false; #endif /* COMPILER2 */ } *fr_addr = ret_frame; return true; } // nothing else to try return false; } void JavaThread::cache_global_variables() { }