From 3b0750b6ed8bc6fef03b3cd4a46b0ccf33e4f4b5 Mon Sep 17 00:00:00 2001 From: Gabriel Corona Date: Tue, 9 Dec 2014 12:17:18 +0100 Subject: [PATCH] [mm] Allow to disable the mm based `malloc` at runtime The goal is to enable the mm based `malloc` only when needed and fall back to the (more efficient) builtin/next implementation when it is not needed: * run instrospection-less jobs without it; * whene the MC and the application are in different processes, the MC will be able to run with the standard `malloc` and the application will use mm. As malloc is needed very early in the application initialisation, an environment variable is used to change the behaviour. --- src/mc/mc_checkpoint.c | 1 - src/mc/mc_memory.c | 5 - src/xbt/mmalloc/mm_legacy.c | 201 +++++++++++------------------------- src/xbt/mmalloc/mm_module.c | 4 - 4 files changed, 61 insertions(+), 150 deletions(-) diff --git a/src/mc/mc_checkpoint.c b/src/mc/mc_checkpoint.c index 0f3cb094a7..73313227bc 100644 --- a/src/mc/mc_checkpoint.c +++ b/src/mc/mc_checkpoint.c @@ -247,7 +247,6 @@ static void MC_get_memory_regions(mc_snapshot_t snapshot) { const mc_process_t process = &mc_model_checker->process; const size_t n = process->object_infos_size; - snapshot->snapshot_regions_count = n + 1; snapshot->snapshot_regions = xbt_new0(mc_mem_region_t, n + 1); diff --git a/src/mc/mc_memory.c b/src/mc/mc_memory.c index cfabdfcf33..d1c804bed1 100644 --- a/src/mc/mc_memory.c +++ b/src/mc/mc_memory.c @@ -28,17 +28,12 @@ void MC_memory_init() std_heap = mmalloc_get_default_md(); xbt_assert(std_heap != NULL); -#if 0 && defined HAVE_GNU_LD && !defined MMALLOC_WANT_OVERRIDE_LEGACY - /* use the system malloc for the model-checker data */ - mc_heap = NULL; -#else /* Create the second region a page after the first one ends + safety gap */ mc_heap = xbt_mheap_new_options(-1, (char *) (std_heap) + STD_HEAP_SIZE + xbt_pagesize, 0); xbt_assert(mc_heap != NULL); -#endif } /* Finalize the memory subsystem */ diff --git a/src/xbt/mmalloc/mm_legacy.c b/src/xbt/mmalloc/mm_legacy.c index 3d58ba5929..f62d331b3f 100644 --- a/src/xbt/mmalloc/mm_legacy.c +++ b/src/xbt/mmalloc/mm_legacy.c @@ -5,6 +5,8 @@ * under the terms of the license (GNU LGPL) which comes with this package. */ /* Redefine the classical malloc/free/realloc functions so that they fit well in the mmalloc framework */ +#define _GNU_SOURCE +#include #include "mmprivate.h" #include "xbt_modinter.h" @@ -32,191 +34,110 @@ void mmalloc_set_current_heap(xbt_mheap_t new_heap) __mmalloc_current_heap = new_heap; } - #ifdef MMALLOC_WANT_OVERRIDE_LEGACY -#if 0 && defined(HAVE_GNU_LD) - -#undef _GNU_SOURCE -#define _GNU_SOURCE 1 -#include - -static void * (*real_malloc) (size_t) = NULL; -static void * (*real_realloc) (void*,size_t) = NULL; -static void * (*real_free) (void*) = NULL; - -static void mm_gnuld_legacy_init(void) { /* This function is called from mmalloc_preinit(); it works even if it's static because all mm is in mm.c */ - real_malloc = (void * (*) (size_t)) dlsym(RTLD_NEXT, "malloc"); - real_realloc = (void * (*) (void*,size_t)) dlsym(RTLD_NEXT, "realloc"); - real_free = (void * (*) (void*)) dlsym(RTLD_NEXT, "free"); - __mmalloc_current_heap = __mmalloc_default_mdp; -} -/* Hello pimple! - * DL needs some memory while resolving the malloc symbol, that is somehow problematic - * To that extend, we have a little area here living in .BSS that we return if asked for memory before the malloc is resolved. +/* Fake implementations, they are used to fool dlsym: + * dlsym used calloc and falls back to some other mechanism + * if this fails. */ -static int allocated_junk = 0; /* keep track of many blocks of our little area was already given to someone */ -#define JUNK_SIZE 8 -#define MAX_JUNK_AREAS (64 * 1024 / JUNK_SIZE) -static char junkareas[MAX_JUNK_AREAS][JUNK_SIZE]; - -/* This version use mmalloc if there is a current heap, or the legacy implem if not */ -static void *malloc_or_calloc(size_t n, int setzero) { - xbt_mheap_t mdp = __mmalloc_current_heap; - void *ret; -#ifdef MM_LEGACY_VERBOSE - static int warned_raw = 0; - static int warned_mmalloc = 0; -#endif - - if (mdp) { - LOCK(mdp); - ret = mmalloc(mdp, n); - UNLOCK(mdp); - // This was already done by mmalloc: - if (mdp->options & XBT_MHEAP_OPTION_MEMSET) { - setzero = 0; - } -#ifdef MM_LEGACY_VERBOSE - if (!warned_mmalloc) { - fprintf(stderr,"Using mmalloc; enabling the model-checker in cmake may have a bad impact on your simulation performance\n"); - warned_mmalloc = 1; - } -#endif - } else if (!real_malloc) { - size_t needed_areas = n / JUNK_SIZE; - if(needed_areas * JUNK_SIZE != n) needed_areas++; - if (allocated_junk+needed_areas>=MAX_JUNK_AREAS) { - fprintf(stderr, - "Panic: real malloc symbol not resolved yet, and I already gave my little private memory chunk away.\n"); - exit(1); - } else { - size_t i = allocated_junk; - allocated_junk += needed_areas; - ret = junkareas[i]; - } - } - else { -#ifdef MM_LEGACY_VERBOSE - if (!warned_raw) { - fprintf(stderr,"Using system malloc after interception; you seem to be currently model-checking\n"); - warned_raw = 1; - } -#endif - ret = real_malloc(n); - } - if (ret && setzero) { - memset(ret, 0, n); - } - return ret; -} - -void *malloc(size_t n) -{ - return malloc_or_calloc(n, 0); -} +static void* mm_fake_calloc(size_t nmemb, size_t size) { return NULL; } +static void* mm_fake_malloc(size_t n) { return NULL; } +static void* mm_fake_realloc(void *p, size_t s) { return NULL; } -void *calloc(size_t nmemb, size_t size) -{ - return malloc_or_calloc(nmemb*size, 1); -} +/* Function signatures for the main malloc functions: */ +typedef void* (*mm_malloc_t)(size_t size); +typedef void (*mm_free_t)(void*); +typedef void* (*mm_calloc_t)(size_t nmemb, size_t size); +typedef void* (*mm_realloc_t)(void *ptr, size_t size); -void *realloc(void *p, size_t s) -{ - xbt_mheap_t mdp = __mmalloc_current_heap; - void *ret; - - if (mdp) { - LOCK(mdp); - ret = mrealloc(mdp, p, s); - UNLOCK(mdp); - } else { - ret = real_realloc(p,s); - } +/* Function pointers to the real/next implementations: */ +static mm_malloc_t mm_real_malloc = mm_fake_malloc; +static mm_free_t mm_real_free; +static mm_calloc_t mm_real_calloc = mm_fake_calloc; +static mm_realloc_t mm_real_realloc = mm_fake_realloc; - return ret; -} +#define GET_HEAP() __mmalloc_current_heap -void free(void *p) +/** Constructor functions used to initialize the malloc implementation + */ +static void __attribute__((constructor(101))) mm_legacy_constructor() { - if (p==NULL) - return; - if (p<(void*)junkareas || p>=(void*)(junkareas[MAX_JUNK_AREAS]) ) { - // main use case - - xbt_mheap_t mdp = __mmalloc_current_heap; - - if (mdp) { - LOCK(mdp); - mfree(mdp, p); - UNLOCK(mdp); - } else { - real_free(p); - } + bool use_mm = !getenv("SIMGRID_MALLOC_NO_USE_MM"); + if (use_mm) { + __mmalloc_current_heap = mmalloc_preinit(); } else { - // We are in the junkarea. - // This area is used to allocate memory at initilization time. - - if(allocated_junk && p==junkareas[allocated_junk-1]) { - // Last junkarea. We can reuse it. - allocated_junk--; - } else { - // We currently cannot reuse freed junkareas in the general case. - } + mm_real_realloc = (mm_realloc_t) dlsym(RTLD_NEXT, "realloc"); + mm_real_malloc = (mm_malloc_t) dlsym(RTLD_NEXT, "malloc"); + mm_real_free = (mm_free_t) dlsym(RTLD_NEXT, "free"); + mm_real_calloc = (mm_calloc_t) dlsym(RTLD_NEXT, "calloc"); } } - -#else /* NO GNU_LD */ void *malloc(size_t n) { - xbt_mheap_t mdp = __mmalloc_current_heap ?: (xbt_mheap_t) mmalloc_preinit(); + if (!__mmalloc_current_heap) { + return mm_real_malloc(n); + } + + xbt_mheap_t mdp = GET_HEAP(); + if (!mdp) + return NULL; LOCK(mdp); void *ret = mmalloc(mdp, n); UNLOCK(mdp); - - return ret; } void *calloc(size_t nmemb, size_t size) { - xbt_mheap_t mdp = __mmalloc_current_heap ?: (xbt_mheap_t) mmalloc_preinit(); + if (!__mmalloc_current_heap) { + return mm_real_calloc(nmemb, size); + } + + xbt_mheap_t mdp = GET_HEAP(); + if (!mdp) + return NULL; LOCK(mdp); void *ret = mmalloc(mdp, nmemb*size); UNLOCK(mdp); - // This was already done in the callee: if(!(mdp->options & XBT_MHEAP_OPTION_MEMSET)) { memset(ret, 0, nmemb * size); } - return ret; } void *realloc(void *p, size_t s) { - void *ret = NULL; - xbt_mheap_t mdp = __mmalloc_current_heap ?: (xbt_mheap_t) mmalloc_preinit(); + if (!__mmalloc_current_heap) { + return mm_real_realloc(p, s); + } + + xbt_mheap_t mdp = GET_HEAP(); + if (!mdp) + return NULL; LOCK(mdp); - ret = mrealloc(mdp, p, s); + void* ret = mrealloc(mdp, p, s); UNLOCK(mdp); - return ret; } void free(void *p) { - if (p != NULL) { - xbt_mheap_t mdp = __mmalloc_current_heap ?: (xbt_mheap_t) mmalloc_preinit(); + if (!p) + return; - LOCK(mdp); - mfree(mdp, p); - UNLOCK(mdp); + if (!__mmalloc_current_heap) { + mm_real_free(p); + return; } + + xbt_mheap_t mdp = GET_HEAP(); + LOCK(mdp); + mfree(mdp, p); + UNLOCK(mdp); } -#endif /* NO GNU_LD */ #endif /* WANT_MALLOC_OVERRIDE */ diff --git a/src/xbt/mmalloc/mm_module.c b/src/xbt/mmalloc/mm_module.c index 86c342163b..d553f4af67 100644 --- a/src/xbt/mmalloc/mm_module.c +++ b/src/xbt/mmalloc/mm_module.c @@ -343,10 +343,6 @@ void *mmalloc_preinit(void) } xbt_assert(__mmalloc_default_mdp != NULL); -#if 0 && defined(HAVE_GNU_LD) && defined(MMALLOC_WANT_OVERRIDE_LEGACY) - mm_gnuld_legacy_init(); -#endif - return __mmalloc_default_mdp; } -- 2.20.1