a49f53e60f
GPL license does not require all files to have the copyright notice and header. To save some space, I removed the headers from all files except the executables and the main Python module.
84 lines
2.4 KiB
C
84 lines
2.4 KiB
C
/*
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* malloc_trim_ldp: A ld-preload library that can be used to potentially
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* save memory (especially for long running larger apps).
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*
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* Copyright (C) 2008-2012 Red Hat, Inc.
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* Authors: Phil Knirsch
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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*
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* To compile:
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* gcc -Wall -fPIC -shared -lpthread -o malloc_trim_ldp.o malloc_trim_ldp.c
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*
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* To install:
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* For a single app:
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* LD_PRELOAD=./malloc_trim_ldp.o application
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*
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* Systemwide:
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* cp malloc_trim_ldp.o /lib
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* echo "/lib/malloc_trim_ldp.o" >> /etc/ld.so.preload
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*
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* How it works:
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* This ld-preload library simply redirects the glibc free() call to a new
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* one that simply has a static counter and every 10.000 free() calls will
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* call malloc_trim(0) which goes through the heap of an application and
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* basically releases pages that aren't in use anymore using madvise().
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*
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*/
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#include <malloc.h>
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#include <stdlib.h>
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#include <stdio.h>
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#include <limits.h>
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#include <sys/types.h>
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#include <unistd.h>
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#include <time.h>
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#include <errno.h>
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#include <pthread.h>
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static pthread_mutex_t mymutex = PTHREAD_MUTEX_INITIALIZER;
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static int malloc_trim_count=0;
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static void mymalloc_install (void);
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static void mymalloc_uninstall (void);
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static void (*old_free_hook) (void *, const void *);
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static void myfree(void *ptr, const void *caller)
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{
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pthread_mutex_lock(&mymutex);
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malloc_trim_count++;
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if(malloc_trim_count%10000 == 0) {
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malloc_trim(0);
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}
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mymalloc_uninstall();
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free(ptr);
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mymalloc_install();
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pthread_mutex_unlock(&mymutex);
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}
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static void mymalloc_install (void)
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{
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old_free_hook = __free_hook;
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__free_hook = myfree;
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}
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static void mymalloc_uninstall (void)
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{
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__free_hook = old_free_hook;
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}
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void (*__malloc_initialize_hook) (void) = mymalloc_install;
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