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Diffstat (limited to 'man3/mallinfo.3')
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diff --git a/man3/mallinfo.3 b/man3/mallinfo.3 deleted file mode 100644 index 452abedc9..000000000 --- a/man3/mallinfo.3 +++ /dev/null @@ -1,338 +0,0 @@ -'\" t -.\" Copyright (c) 2012 by Michael Kerrisk <mtk.manpages@gmail.com> -.\" -.\" SPDX-License-Identifier: Linux-man-pages-copyleft -.\" -.TH mallinfo 3 (date) "Linux man-pages (unreleased)" -.SH NAME -mallinfo, mallinfo2 \- obtain memory allocation information -.SH LIBRARY -Standard C library -.RI ( libc ", " \-lc ) -.SH SYNOPSIS -.nf -.B #include <malloc.h> -.PP -.B struct mallinfo mallinfo(void); -.B struct mallinfo2 mallinfo2(void); -.fi -.SH DESCRIPTION -These functions return a copy of a structure containing information about -memory allocations performed by -.BR malloc (3) -and related functions. -The structure returned by each function contains the same fields. -However, the older function, -.BR mallinfo (), -is deprecated since the type used for the fields is too small (see BUGS). -.PP -Note that not all allocations are visible to these functions; -see BUGS and consider using -.BR malloc_info (3) -instead. -.PP -The -.I mallinfo2 -structure returned by -.BR mallinfo2 () -is defined as follows: -.PP -.in +4n -.EX -struct mallinfo2 { - size_t arena; /* Non\-mmapped space allocated (bytes) */ - size_t ordblks; /* Number of free chunks */ - size_t smblks; /* Number of free fastbin blocks */ - size_t hblks; /* Number of mmapped regions */ - size_t hblkhd; /* Space allocated in mmapped regions - (bytes) */ - size_t usmblks; /* See below */ - size_t fsmblks; /* Space in freed fastbin blocks (bytes) */ - size_t uordblks; /* Total allocated space (bytes) */ - size_t fordblks; /* Total free space (bytes) */ - size_t keepcost; /* Top\-most, releasable space (bytes) */ -}; -.EE -.in -.PP -The -.I mallinfo -structure returned by the deprecated -.BR mallinfo () -function is exactly the same, except that the fields are typed as -.IR int . -.PP -The structure fields contain the following information: -.TP 10 -.I arena -The total amount of memory allocated by means other than -.BR mmap (2) -(i.e., memory allocated on the heap). -This figure includes both in-use blocks and blocks on the free list. -.TP -.I ordblks -The number of ordinary (i.e., non-fastbin) free blocks. -.TP -.I smblks -.\" the glibc info page wrongly says this field is unused -.\" https://sourceware.org/bugzilla/show_bug.cgi?id=26746 -The number of fastbin free blocks (see -.BR mallopt (3)). -.TP -.I hblks -The number of blocks currently allocated using -.BR mmap (2). -(See the discussion of -.B M_MMAP_THRESHOLD -in -.BR mallopt (3).) -.TP -.I hblkhd -The number of bytes in blocks currently allocated using -.BR mmap (2). -.TP -.I usmblks -This field is unused, and is always 0. -.\" It seems to have been zero since at least as far back as glibc 2.15 -Historically, it was the "highwater mark" for allocated space\[em]that is, -the maximum amount of space that was ever allocated (in bytes); -this field was maintained only in nonthreading environments. -.TP -.I fsmblks -.\" the glibc info page wrongly says this field is unused -.\" https://sourceware.org/bugzilla/show_bug.cgi?id=26746 -The total number of bytes in fastbin free blocks. -.TP -.I uordblks -The total number of bytes used by in-use allocations. -.TP -.I fordblks -The total number of bytes in free blocks. -.TP -.I keepcost -The total amount of releasable free space at the top -of the heap. -This is the maximum number of bytes that could ideally -(i.e., ignoring page alignment restrictions, and so on) be released by -.BR malloc_trim (3). -.SH ATTRIBUTES -For an explanation of the terms used in this section, see -.BR attributes (7). -.ad l -.nh -.TS -allbox; -lb lb lbx -l l l. -Interface Attribute Value -T{ -.BR mallinfo (), -.BR mallinfo2 () -T} Thread safety T{ -MT-Unsafe init const:mallopt -T} -.TE -.hy -.ad -.sp 1 -.BR mallinfo ()/ -.BR mallinfo2 () -would access some global internal objects. -If modify them with non-atomically, -may get inconsistent results. -The identifier -.I mallopt -in -.I const:mallopt -mean that -.BR mallopt () -would modify the global internal objects with atomics, that make sure -.BR mallinfo ()/ -.BR mallinfo2 () -is safe enough, others modify with non-atomically maybe not. -.SH STANDARDS -None. -.SH HISTORY -.TP -.BR mallinfo () -glibc 2.0. -SVID. -.TP -.BR mallinfo2 () -.\" commit e3960d1c57e57f33e0e846d615788f4ede73b945 -glibc 2.33. -.SH BUGS -.\" FIXME . http://sourceware.org/bugzilla/show_bug.cgi?id=208 -.\" See the 24 Aug 2011 mail by Paul Pluzhnikov: -.\" "[patch] Fix mallinfo() to accumulate results for all arenas" -.\" on libc-alpha@sourceware.org -.B Information is returned for only the main memory allocation area. -Allocations in other arenas are excluded. -See -.BR malloc_stats (3) -and -.BR malloc_info (3) -for alternatives that include information about other arenas. -.PP -The fields of the -.I mallinfo -structure that is returned by the older -.BR mallinfo () -function are typed as -.IR int . -However, because some internal bookkeeping values may be of type -.IR long , -the reported values may wrap around zero and thus be inaccurate. -.SH EXAMPLES -The program below employs -.BR mallinfo2 () -to retrieve memory allocation statistics before and after -allocating and freeing some blocks of memory. -The statistics are displayed on standard output. -.PP -The first two command-line arguments specify the number and size of -blocks to be allocated with -.BR malloc (3). -.PP -The remaining three arguments specify which of the allocated blocks -should be freed with -.BR free (3). -These three arguments are optional, and specify (in order): -the step size to be used in the loop that frees blocks -(the default is 1, meaning free all blocks in the range); -the ordinal position of the first block to be freed -(default 0, meaning the first allocated block); -and a number one greater than the ordinal position -of the last block to be freed -(default is one greater than the maximum block number). -If these three arguments are omitted, -then the defaults cause all allocated blocks to be freed. -.PP -In the following example run of the program, -1000 allocations of 100 bytes are performed, -and then every second allocated block is freed: -.PP -.in +4n -.EX -$ \fB./a.out 1000 100 2\fP -============== Before allocating blocks ============== -Total non\-mmapped bytes (arena): 0 -# of free chunks (ordblks): 1 -# of free fastbin blocks (smblks): 0 -# of mapped regions (hblks): 0 -Bytes in mapped regions (hblkhd): 0 -Max. total allocated space (usmblks): 0 -Free bytes held in fastbins (fsmblks): 0 -Total allocated space (uordblks): 0 -Total free space (fordblks): 0 -Topmost releasable block (keepcost): 0 -\& -============== After allocating blocks ============== -Total non\-mmapped bytes (arena): 135168 -# of free chunks (ordblks): 1 -# of free fastbin blocks (smblks): 0 -# of mapped regions (hblks): 0 -Bytes in mapped regions (hblkhd): 0 -Max. total allocated space (usmblks): 0 -Free bytes held in fastbins (fsmblks): 0 -Total allocated space (uordblks): 104000 -Total free space (fordblks): 31168 -Topmost releasable block (keepcost): 31168 -\& -============== After freeing blocks ============== -Total non\-mmapped bytes (arena): 135168 -# of free chunks (ordblks): 501 -# of free fastbin blocks (smblks): 0 -# of mapped regions (hblks): 0 -Bytes in mapped regions (hblkhd): 0 -Max. total allocated space (usmblks): 0 -Free bytes held in fastbins (fsmblks): 0 -Total allocated space (uordblks): 52000 -Total free space (fordblks): 83168 -Topmost releasable block (keepcost): 31168 -.EE -.in -.SS Program source -\& -.\" SRC BEGIN (mallinfo.c) -.EX -#include <malloc.h> -#include <stdlib.h> -#include <string.h> -\& -static void -display_mallinfo2(void) -{ - struct mallinfo2 mi; -\& - mi = mallinfo2(); -\& - printf("Total non\-mmapped bytes (arena): %zu\en", mi.arena); - printf("# of free chunks (ordblks): %zu\en", mi.ordblks); - printf("# of free fastbin blocks (smblks): %zu\en", mi.smblks); - printf("# of mapped regions (hblks): %zu\en", mi.hblks); - printf("Bytes in mapped regions (hblkhd): %zu\en", mi.hblkhd); - printf("Max. total allocated space (usmblks): %zu\en", mi.usmblks); - printf("Free bytes held in fastbins (fsmblks): %zu\en", mi.fsmblks); - printf("Total allocated space (uordblks): %zu\en", mi.uordblks); - printf("Total free space (fordblks): %zu\en", mi.fordblks); - printf("Topmost releasable block (keepcost): %zu\en", mi.keepcost); -} -\& -int -main(int argc, char *argv[]) -{ -#define MAX_ALLOCS 2000000 - char *alloc[MAX_ALLOCS]; - size_t blockSize, numBlocks, freeBegin, freeEnd, freeStep; -\& - if (argc < 3 || strcmp(argv[1], "\-\-help") == 0) { - fprintf(stderr, "%s num\-blocks block\-size [free\-step " - "[start\-free [end\-free]]]\en", argv[0]); - exit(EXIT_FAILURE); - } -\& - numBlocks = atoi(argv[1]); - blockSize = atoi(argv[2]); - freeStep = (argc > 3) ? atoi(argv[3]) : 1; - freeBegin = (argc > 4) ? atoi(argv[4]) : 0; - freeEnd = (argc > 5) ? atoi(argv[5]) : numBlocks; -\& - printf("============== Before allocating blocks ==============\en"); - display_mallinfo2(); -\& - for (size_t j = 0; j < numBlocks; j++) { - if (numBlocks >= MAX_ALLOCS) { - fprintf(stderr, "Too many allocations\en"); - exit(EXIT_FAILURE); - } -\& - alloc[j] = malloc(blockSize); - if (alloc[j] == NULL) { - perror("malloc"); - exit(EXIT_FAILURE); - } - } -\& - printf("\en============== After allocating blocks ==============\en"); - display_mallinfo2(); -\& - for (size_t j = freeBegin; j < freeEnd; j += freeStep) - free(alloc[j]); -\& - printf("\en============== After freeing blocks ==============\en"); - display_mallinfo2(); -\& - exit(EXIT_SUCCESS); -} -.EE -.\" SRC END -.SH SEE ALSO -.ad l -.nh -.BR mmap (2), -.BR malloc (3), -.BR malloc_info (3), -.BR malloc_stats (3), -.BR malloc_trim (3), -.BR mallopt (3) |