让程序飞 之 内存工具:valgrind –tool=massif & massif-visualizer
之前提到过内存泄漏问题，我们有memcheck工具来检查。很爽。但是有时候memcheck工具查了没泄漏，程序一跑，内存还是狂飙。这又是什么问题。。。
其实memcheck检查的内存泄漏只是狭义的内存泄漏，或者说是严格的内存泄漏，也就是说，在程序运行的生命周期内，这部分内存你是彻底释放不了了，即，你失去了这些地址。
其实还有第二种类型的内存泄漏，就是，长期闲置的内存堆积。这部分内存虽然你还保存了地址，想要释放的时候还是能释放。关键就是你忘了释放。。。杯具啊。这种问题memcheck就不给力了。这就引出了第二个内存工具valgrind –tool=massif。
先来看一个程序：
#include <iostream>
#include <vector>
using namespace std;
vector< int *> va, vb;
void fa() {
int *p = new int [100];
va.push_back(p);
}
void fb() {
int *p = new int [100];
vb.push_back(p);
}
int main() {
for ( int i=0; i<100000; i++) {
fa();
fb();
}
return 0;
}
程序里，我们拼命申请内存，然后放起来，不用。显然，这种程序跑起来内存肯定一路狂飙，直到内存耗尽而亡。。。
面对这种程序，我们需要一个工具来找出我们分配的内存都用到哪里了。massif就是这个工具。二话不说，先编译之：
g++ –o test –g test.cpp
交给massif运行之：
valgrind --tool=massif ./test
什么都没输出？不是的，看看当前目录，多了massif.out.****的文件吧，那才是massif真正的输出。vi打开。乱码！！！人类看不懂。其实这个输出还要经过一道工序加工我们人类才能看懂：
ms_print massif.out.*** >massif.log
打开log看看：
--------------------------------------------------------------------------------
Command: ./mem1
Massif arguments: (none)
ms_print arguments: massif.out.20770
--------------------------------------------------------------------------------
MB
79.82^ #
| ::#
| ::@:::#
| :::::@:::#
| :::@:::::@:::#
| ::::::@:::::@:::#
| :::@:::::@:::::@:::#
| @:::::@:::::@:::::@:::#
| ::::@:::::@:::::@:::::@:::#
| :@:::::@:::::@:::::@:::::@:::#
| ::::@:::::@:::::@:::::@:::::@:::#
| ::::::::@:::::@:::::@:::::@:::::@:::#
| ::::::::::::@:::::@:::::@:::::@:::::@:::#
| ::::::::::::::@:::::@:::::@:::::@:::::@:::#
| ::@:::::::::::::::@:::::@:::::@:::::@:::::@:::#
| ::::::@:::::::::::::::@:::::@:::::@:::::@:::::@:::#
| :::::::::@:::::::::::::::@:::::@:::::@:::::@:::::@:::#
| @:::::::::::@:::::::::::::::@:::::@:::::@:::::@:::::@:::#
| :::@:::::::::::@:::::::::::::::@:::::@:::::@:::::@:::::@:::#
| :::::::@:::::::::::@:::::::::::::::@:::::@:::::@:::::@:::::@:::#
0 +----------------------------------------------------------------------->Mi
0 20.69
Number of snapshots: 98
Detailed snapshots: [13, 28, 51, 59, 69, 79, 89, 97 (peak)]
--------------------------------------------------------------------------------
n time(i) total(B) useful-heap(B) extra-heap(B) stacks(B)
--------------------------------------------------------------------------------
0 0 0 0 0 0
1 1,463,114 408 400 8 0
2 1,800,331 1,285,344 1,260,768 24,576 0
3 2,133,198 2,657,576 2,606,736 50,840 0
4 2,348,502 3,525,648 3,459,072 66,576 0
5 2,624,527 4,680,696 4,591,472 89,224 0
6 2,967,727 6,116,856 5,999,472 117,384 0
7 3,206,290 7,057,808 6,924,544 133,264 0
8 3,416,890 7,939,088 7,788,544 150,544 0
9 3,666,980 8,985,608 8,814,544 171,064 0
10 3,912,680 10,013,768 9,822,544 191,224 0
11 4,158,380 11,041,928 10,830,544 211,384 0
12 4,404,080 12,070,088 11,838,544 231,544 0
13 4,649,780 13,098,248 12,846,544 251,704 0
98.08% (12,846,544B) (heap allocation functions) malloc/new/new[], --alloc-fns, etc.
->48.04% (6,292,400B) 0x400A14: fa() (mem1.cpp:8)
| ->48.04% (6,292,400B) 0x400A6A: main (mem1.cpp:20)
|
->48.04% (6,292,000B) 0x400A3D: fb() (mem1.cpp:13)
| ->48.04% (6,292,000B) 0x400A6F: main (mem1.cpp:21)
|
->02.00% (262,144B) 0x40142F: __gnu_cxx::new_allocator<int*>::allocate(unsigned long, void const*) (new_allocator.h:89)
->02.00% (262,144B) 0x40121B: std::_Vector_base<int*, std::allocator<int*> >::_M_allocate(unsigned long) (stl_vector.h:140)
->02.00% (262,144B) 0x400DC5: std::vector<int*, std::allocator<int*> >::_M_insert_aux(__gnu_cxx::__normal_iterator<int**, std::vector<int*, std::allocator<int*> > >, int* const&) (vector.tcc:322)
->02.00% (262,144B) 0x400BC4: std::vector<int*, std::allocator<int*> >::push_back(int* const&) (stl_vector.h:741)
->01.00% (131,072B) 0x400A29: fa() (mem1.cpp:9)
| ->01.00% (131,072B) 0x400A6A: main (mem1.cpp:20)
|
->01.00% (131,072B) 0x400A52: fb() (mem1.cpp:14)
->01.00% (131,072B) 0x400A6F: main (mem1.cpp:21)
--------------------------------------------------------------------------------
n time(i) total(B) useful-heap(B) extra-heap(B) stacks(B)
--------------------------------------------------------------------------------
14 5,019,101 14,537,472 14,262,688 274,784 0
15 5,339,391 15,877,752 15,576,688 301,064 0
16 5,549,991 16,759,032 16,440,688 318,344 0
17 5,760,591 17,640,312 17,304,688 335,624 0
18 5,971,191 18,521,592 18,168,688 352,904 0
19 6,181,791 19,402,872 19,032,688 370,184 0
20 6,392,391 20,284,152 19,896,688 387,464 0
21 6,602,991 21,165,432 20,760,688 404,744 0
22 6,813,591 22,046,712 21,624,688 422,024 0
23 7,024,191 22,927,992 22,488,688 439,304 0
24 7,234,791 23,809,272 23,352,688 456,584 0
25 7,445,391 24,690,552 24,216,688 473,864 0
26 7,655,991 25,571,832 25,080,688 491,144 0
27 7,964,871 26,864,376 26,347,888 516,488 0
28 8,147,289 27,787,696 27,263,376 524,320 0
98.11% (27,263,376B) (heap allocation functions) malloc/new/new[], --alloc-fns, etc.
->47.17% (13,107,600B) 0x400A14: fa() (mem1.cpp:8)
| ->47.17% (13,107,600B) 0x400A6A: main (mem1.cpp:20)
|
->47.17% (13,107,200B) 0x400A3D: fb() (mem1.cpp:13)
| ->47.17% (13,107,200B) 0x400A6F: main (mem1.cpp:21)
|
->03.77% (1,048,576B) 0x40142F: __gnu_cxx::new_allocator<int*>::allocate(unsigned long, void const*) (new_allocator.h:89)
->03.77% (1,048,576B) 0x40121B: std::_Vector_base<int*, std::allocator<int*> >::_M_allocate(unsigned long) (stl_vector.h:140)
->03.77% (1,048,576B) 0x400DC5: std::vector<int*, std::allocator<int*> >::_M_insert_aux(__gnu_cxx::__normal_iterator<int**, std::vector<int*, std::allocator<int*> > >, int* const&) (vector.tcc:322)
->03.77% (1,048,576B) 0x400BC4: std::vector<int*, std::allocator<int*> >::push_back(int* const&) (stl_vector.h:741)
->02.83% (786,432B) 0x400A29: fa() (mem1.cpp:9)
| ->02.83% (786,432B) 0x400A6A: main (mem1.cpp:20)
|
->00.94% (262,144B) in 1+ places, all below ms_print's threshold (01.00%)
--------------------------------------------------------------------------------
n time(i) total(B) useful-heap(B) extra-heap(B) stacks(B)
--------------------------------------------------------------------------------
29 8,442,148 28,657,544 28,116,176 541,368 0
30 8,835,268 30,302,600 29,728,976 573,624 0
31 9,228,388 31,947,656 31,341,776 605,880 0
32 9,424,948 32,770,184 32,148,176 622,008 0
33 9,621,508 33,592,712 32,954,576 638,136 0
34 9,818,068 34,415,240 33,760,976 654,264 0
35 10,014,628 35,237,768 34,567,376 670,392 0
36 10,211,188 36,060,296 35,373,776 686,520 0
37 10,407,748 36,882,824 36,180,176 702,648 0
38 10,604,308 37,705,352 36,986,576 718,776 0
39 10,800,868 38,527,880 37,792,976 734,904 0
40 10,997,428 39,350,408 38,599,376 751,032 0
41 11,193,988 40,172,936 39,405,776 767,160 0
42 11,390,548 40,995,464 40,212,176 783,288 0
43 11,587,108 41,817,992 41,018,576 799,416 0
44 11,783,668 42,640,520 41,824,976 815,544 0
45 11,980,228 43,463,048 42,631,376 831,672 0
46 12,176,788 44,285,576 43,437,776 847,800 0
47 12,373,348 45,108,104 44,244,176 863,928 0
48 12,569,908 45,930,632 45,050,576 880,056 0
49 12,864,748 47,164,424 46,260,176 904,248 0
50 13,047,168 47,927,792 47,008,576 919,216 0
51 13,229,593 48,691,160 47,756,976 934,184 0
98.08% (47,756,976B) (heap allocation functions) malloc/new/new[], --alloc-fns, etc.
->47.96% (23,354,400B) 0x400A14: fa() (mem1.cpp:8)
| ->47.96% (23,354,400B) 0x400A6A: main (mem1.cpp:20)
|
->47.96% (23,354,000B) 0x400A3D: fb() (mem1.cpp:13)
| ->47.96% (23,354,000B) 0x400A6F: main (mem1.cpp:21)
|
->02.15% (1,048,576B) 0x40142F: __gnu_cxx::new_allocator<int*>::allocate(unsigned long, void const*) (new_allocator.h:89)
->02.15% (1,048,576B) 0x40121B: std::_Vector_base<int*, std::allocator<int*> >::_M_allocate(unsigned long) (stl_vector.h:140)
->02.15% (1,048,576B) 0x400DC5: std::vector<int*, std::allocator<int*> >::_M_insert_aux(__gnu_cxx::__normal_iterator<int**, std::vector<int*, std::allocator<int*> > >, int* const&) (vector.tcc:322)
->02.15% (1,048,576B) 0x400BC4: std::vector<int*, std::allocator<int*> >::push_back(int* const&) (stl_vector.h:741)
->01.08% (524,288B) 0x400A29: fa() (mem1.cpp:9)
| ->01.08% (524,288B) 0x400A6A: main (mem1.cpp:20)
|
->01.08% (524,288B) 0x400A52: fb() (mem1.cpp:14)
->01.08% (524,288B) 0x400A6F: main (mem1.cpp:21)
--------------------------------------------------------------------------------
n time(i) total(B) useful-heap(B) extra-heap(B) stacks(B)
--------------------------------------------------------------------------------
52 13,412,013 49,454,528 48,505,376 949,152 0
53 13,594,438 50,217,896 49,253,776 964,120 0
54 13,776,858 50,981,264 50,002,176 979,088 0
55 13,959,283 51,744,632 50,750,576 994,056 0
56 14,141,703 52,508,000 51,498,976 1,009,024 0
57 14,324,128 53,271,368 52,247,376 1,023,992 0
58 14,506,548 54,034,736 52,995,776 1,038,960 0
59 14,797,117 55,574,960 54,526,352 1,048,608 0
98.11% (54,526,352B) (heap allocation functions) malloc/new/new[], --alloc-fns, etc.
->47.17% (26,214,800B) 0x400A14: fa() (mem1.cpp:8)
| ->47.17% (26,214,800B) 0x400A6A: main (mem1.cpp:20)
|
->47.17% (26,214,400B) 0x400A3D: fb() (mem1.cpp:13)
| ->47.17% (26,214,400B) 0x400A6F: main (mem1.cpp:21)
|
->03.77% (2,097,152B) 0x40142F: __gnu_cxx::new_allocator<int*>::allocate(unsigned long, void const*) (new_allocator.h:89)
->03.77% (2,097,152B) 0x40121B: std::_Vector_base<int*, std::allocator<int*> >::_M_allocate(unsigned long) (stl_vector.h:140)
->03.77% (2,097,152B) 0x400DC5: std::vector<int*, std::allocator<int*> >::_M_insert_aux(__gnu_cxx::__normal_iterator<int**, std::vector<int*, std::allocator<int*> > >, int* const&) (vector.tcc:322)
->03.77% (2,097,152B) 0x400BC4: std::vector<int*, std::allocator<int*> >::push_back(int* const&) (stl_vector.h:741)
->02.83% (1,572,864B) 0x400A29: fa() (mem1.cpp:9)
| ->02.83% (1,572,864B) 0x400A6A: main (mem1.cpp:20)
|
->00.94% (524,288B) in 1+ places, all below ms_print's threshold (01.00%)
--------------------------------------------------------------------------------
n time(i) total(B) useful-heap(B) extra-heap(B) stacks(B)
--------------------------------------------------------------------------------
60 14,979,577 55,614,528 54,565,152 1,049,376 0
61 15,162,002 56,377,896 55,313,552 1,064,344 0
62 15,344,422 57,141,264 56,061,952 1,079,312 0
63 15,526,847 57,904,632 56,810,352 1,094,280 0
64 15,709,267 58,668,000 57,558,752 1,109,248 0
65 15,891,692 59,431,368 58,307,152 1,124,216 0
66 16,074,112 60,194,736 59,055,552 1,139,184 0
67 16,256,537 60,958,104 59,803,952 1,154,152 0
68 16,438,957 61,721,472 60,552,352 1,169,120 0
69 16,621,382 62,484,840 61,300,752 1,184,088 0
98.10% (61,300,752B) (heap allocation functions) malloc/new/new[], --alloc-fns, etc.
->47.37% (29,602,000B) 0x400A14: fa() (mem1.cpp:8)
| ->47.37% (29,602,000B) 0x400A6A: main (mem1.cpp:20)
|
->47.37% (29,601,600B) 0x400A3D: fb() (mem1.cpp:13)
| ->47.37% (29,601,600B) 0x400A6F: main (mem1.cpp:21)
|
->03.36% (2,097,152B) 0x40142F: __gnu_cxx::new_allocator<int*>::allocate(unsigned long, void const*) (new_allocator.h:89)
->03.36% (2,097,152B) 0x40121B: std::_Vector_base<int*, std::allocator<int*> >::_M_allocate(unsigned long) (stl_vector.h:140)
->03.36% (2,097,152B) 0x400DC5: std::vector<int*, std::allocator<int*> >::_M_insert_aux(__gnu_cxx::__normal_iterator<int**, std::vector<int*, std::allocator<int*> > >, int* const&) (vector.tcc:322)
->03.36% (2,097,152B) 0x400BC4: std::vector<int*, std::allocator<int*> >::push_back(int* const&) (stl_vector.h:741)
->01.68% (1,048,576B) 0x400A29: fa() (mem1.cpp:9)
| ->01.68% (1,048,576B) 0x400A6A: main (mem1.cpp:20)
|
->01.68% (1,048,576B) 0x400A52: fb() (mem1.cpp:14)
->01.68% (1,048,576B) 0x400A6F: main (mem1.cpp:21)
--------------------------------------------------------------------------------
n time(i) total(B) useful-heap(B) extra-heap(B) stacks(B)
--------------------------------------------------------------------------------
70 16,803,802 63,248,208 62,049,152 1,199,056 0
71 16,986,227 64,011,576 62,797,552 1,214,024 0
72 17,168,647 64,774,944 63,545,952 1,228,992 0
73 17,351,072 65,538,312 64,294,352 1,243,960 0
74 17,533,492 66,301,680 65,042,752 1,258,928 0
75 17,715,917 67,065,048 65,791,152 1,273,896 0
76 17,898,337 67,828,416 66,539,552 1,288,864 0
77 18,080,762 68,591,784 67,287,952 1,303,832 0
78 18,263,182 69,355,152 68,036,352 1,318,800 0
79 18,445,607 70,118,520 68,784,752 1,333,768 0
98.10% (68,784,752B) (heap allocation functions) malloc/new/new[], --alloc-fns, etc.
->47.55% (33,344,000B) 0x400A14: fa() (mem1.cpp:8)
| ->47.55% (33,344,000B) 0x400A6A: main (mem1.cpp:20)
|
->47.55% (33,343,600B) 0x400A3D: fb() (mem1.cpp:13)
| ->47.55% (33,343,600B) 0x400A6F: main (mem1.cpp:21)
|
->02.99% (2,097,152B) 0x40142F: __gnu_cxx::new_allocator<int*>::allocate(unsigned long, void const*) (new_allocator.h:89)
->02.99% (2,097,152B) 0x40121B: std::_Vector_base<int*, std::allocator<int*> >::_M_allocate(unsigned long) (stl_vector.h:140)
->02.99% (2,097,152B) 0x400DC5: std::vector<int*, std::allocator<int*> >::_M_insert_aux(__gnu_cxx::__normal_iterator<int**, std::vector<int*, std::allocator<int*> > >, int* const&) (vector.tcc:322)
->02.99% (2,097,152B) 0x400BC4: std::vector<int*, std::allocator<int*> >::push_back(int* const&) (stl_vector.h:741)
->01.50% (1,048,576B) 0x400A29: fa() (mem1.cpp:9)
| ->01.50% (1,048,576B) 0x400A6A: main (mem1.cpp:20)
|
->01.50% (1,048,576B) 0x400A52: fb() (mem1.cpp:14)
->01.50% (1,048,576B) 0x400A6F: main (mem1.cpp:21)
--------------------------------------------------------------------------------
n time(i) total(B) useful-heap(B) extra-heap(B) stacks(B)
--------------------------------------------------------------------------------
80 18,628,027 70,881,888 69,533,152 1,348,736 0
81 18,810,452 71,645,256 70,281,552 1,363,704 0
82 18,992,872 72,408,624 71,029,952 1,378,672 0
83 19,175,297 73,171,992 71,778,352 1,393,640 0
84 19,357,717 73,935,360 72,526,752 1,408,608 0
85 19,540,142 74,698,728 73,275,152 1,423,576 0
86 19,722,562 75,462,096 74,023,552 1,438,544 0
87 19,904,987 76,225,464 74,771,952 1,453,512 0
88 20,087,407 76,988,832 75,520,352 1,468,480 0
89 20,269,832 77,752,200 76,268,752 1,483,448 0
98.09% (76,268,752B) (heap allocation functions) malloc/new/new[], --alloc-fns, etc.
->47.70% (37,086,000B) 0x400A14: fa() (mem1.cpp:8)
| ->47.70% (37,086,000B) 0x400A6A: main (mem1.cpp:20)
|
->47.70% (37,085,600B) 0x400A3D: fb() (mem1.cpp:13)
| ->47.70% (37,085,600B) 0x400A6F: main (mem1.cpp:21)
|
->02.70% (2,097,152B) 0x40142F: __gnu_cxx::new_allocator<int*>::allocate(unsigned long, void const*) (new_allocator.h:89)
->02.70% (2,097,152B) 0x40121B: std::_Vector_base<int*, std::allocator<int*> >::_M_allocate(unsigned long) (stl_vector.h:140)
->02.70% (2,097,152B) 0x400DC5: std::vector<int*, std::allocator<int*> >::_M_insert_aux(__gnu_cxx::__normal_iterator<int**, std::vector<int*, std::allocator<int*> > >, int* const&) (vector.tcc:322)
->02.70% (2,097,152B) 0x400BC4: std::vector<int*, std::allocator<int*> >::push_back(int* const&) (stl_vector.h:741)
->01.35% (1,048,576B) 0x400A29: fa() (mem1.cpp:9)
| ->01.35% (1,048,576B) 0x400A6A: main (mem1.cpp:20)
|
->01.35% (1,048,576B) 0x400A52: fb() (mem1.cpp:14)
->01.35% (1,048,576B) 0x400A6F: main (mem1.cpp:21)
--------------------------------------------------------------------------------
n time(i) total(B) useful-heap(B) extra-heap(B) stacks(B)
--------------------------------------------------------------------------------
90 20,452,252 78,515,568 77,017,152 1,498,416 0
91 20,634,677 79,278,936 77,765,552 1,513,384 0
92 20,817,097 80,042,304 78,513,952 1,528,352 0
93 20,999,522 80,805,672 79,262,352 1,543,320 0
94 21,181,942 81,569,040 80,010,752 1,558,288 0
95 21,364,367 82,332,408 80,759,152 1,573,256 0
96 21,546,787 83,095,776 81,507,552 1,588,224 0
97 21,690,735 83,697,168 82,097,152 1,600,016 0
98.09% (82,097,152B) (heap allocation functions) malloc/new/new[], --alloc-fns, etc.
->47.79% (40,000,000B) 0x400A14: fa() (mem1.cpp:8)
| ->47.79% (40,000,000B) 0x400A6A: main (mem1.cpp:20)
|
->47.79% (40,000,000B) 0x400A3D: fb() (mem1.cpp:13)
| ->47.79% (40,000,000B) 0x400A6F: main (mem1.cpp:21)
|
->02.51% (2,097,152B) 0x40142F: __gnu_cxx::new_allocator<int*>::allocate(unsigned long, void const*) (new_allocator.h:89)
->02.51% (2,097,152B) 0x40121B: std::_Vector_base<int*, std::allocator<int*> >::_M_allocate(unsigned long) (stl_vector.h:140)
->02.51% (2,097,152B) 0x400DC5: std::vector<int*, std::allocator<int*> >::_M_insert_aux(__gnu_cxx::__normal_iterator<int**, std::vector<int*, std::allocator<int*> > >, int* const&) (vector.tcc:322)
->02.51% (2,097,152B) 0x400BC4: std::vector<int*, std::allocator<int*> >::push_back(int* const&) (stl_vector.h:741)
->01.25% (1,048,576B) 0x400A29: fa() (mem1.cpp:9)
| ->01.25% (1,048,576B) 0x400A6A: main (mem1.cpp:20)
|
->01.25% (1,048,576B) 0x400A52: fb() (mem1.cpp:14)
->01.25% (1,048,576B) 0x400A6F: main (mem1.cpp:21)
不要抓狂，听我给你解释这个输出是什么意思。
massif工作的时候会每隔一定时间对程序的内存使用取个快照。就是上面的一段：
--------------------------------------------------------------------------------
n time(i) total(B) useful-heap(B) extra-heap(B) stacks(B)
--------------------------------------------------------------------------------
60 14,979,577 55,614,528 54,565,152 1,049,376 0
61 15,162,002 56,377,896 55,313,552 1,064,344 0
62 15,344,422 57,141,264 56,061,952 1,079,312 0
63 15,526,847 57,904,632 56,810,352 1,094,280 0
64 15,709,267 58,668,000 57,558,752 1,109,248 0
65 15,891,692 59,431,368 58,307,152 1,124,216 0
66 16,074,112 60,194,736 59,055,552 1,139,184 0
67 16,256,537 60,958,104 59,803,952 1,154,152 0
68 16,438,957 61,721,472 60,552,352 1,169,120 0
69 16,621,382 62,484,840 61,300,752 1,184,088 0
98.10% (61,300,752B) (heap allocation functions) malloc/new/new[], --alloc-fns, etc.
->47.37% (29,602,000B) 0x400A14: fa() (mem1.cpp:8)
| ->47.37% (29,602,000B) 0x400A6A: main (mem1.cpp:20)
|
->47.37% (29,601,600B) 0x400A3D: fb() (mem1.cpp:13)
| ->47.37% (29,601,600B) 0x400A6F: main (mem1.cpp:21)
|
->03.36% (2,097,152B) 0x40142F: __gnu_cxx::new_allocator<int*>::allocate(unsigned long, void const*) (new_allocator.h:89)
->03.36% (2,097,152B) 0x40121B: std::_Vector_base<int*, std::allocator<int*> >::_M_allocate(unsigned long) (stl_vector.h:140)
->03.36% (2,097,152B) 0x400DC5: std::vector<int*, std::allocator<int*> >::_M_insert_aux(__gnu_cxx::__normal_iterator<int**, std::vector<int*, std::allocator<int*> > >, int* const&) (vector.tcc:322)
->03.36% (2,097,152B) 0x400BC4: std::vector<int*, std::allocator<int*> >::push_back(int* const&) (stl_vector.h:741)
->01.68% (1,048,576B) 0x400A29: fa() (mem1.cpp:9)
| ->01.68% (1,048,576B) 0x400A6A: main (mem1.cpp:20)
|
->01.68% (1,048,576B) 0x400A52: fb() (mem1.cpp:14)
->01.68% (1,048,576B) 0x400A6F: main (mem1.cpp:21)
这里我们主要看下半部分，它按照函数调用数的格式输出了每个函数里面每个内存分配点总共分配了多少内存。如上面：函数堆共分配了整个程序的98.10%内存，其中，mem1.cpp第8行的fa() 分配了47.37%，13行的fb也是47.3%。好了，我们知道了，所有的内存都用这俩地方了。。。果断优化。
还有更给力的工具吗？（显然，既然敢提出这个问题，就敢回答yes）
有！massif-visualizer，其实就是massif的图形前端。安装后用它打开刚刚的massif.out.xxxx效果如下：
太爽了！
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