Manual Pages for UNIX Operating System command usage for man meminfo

System Calls                                           meminfo(2)



NAME
     meminfo - provide information about memory

SYNOPSIS
     #include 
     #include 

     int meminfo(const uint64_t inaddr[], int addr_count,
          const uint_t info_req[], int info_count, uint64_t outdata[],
          uint_t validity[]);


PARAMETERS
     inaddr        array of input addresses; the  maximum  number
                   of  addresses  that  can be processed for each
                   call is MAX_MEMINFO_CNT


     addr_count    number of addresses


     info_req      array of types of information requested


     info_count    number of pieces of information requested  for
                   each address in inaddr


     outdata       array into which  results  are  placed;  array
                   size  must  be  the  product of info_count and
                   addr_count


     validity      array of size  addr_count  containing  bitwise
                   result  codes;  0th  bit evaluates validity of
                   corresponding input address, 1st bit  validity
                   of  response  to first member of info_req, and
                   so on


DESCRIPTION
     The meminfo() function provides  information  about  virtual
     and  physical memory particular to the calling process.  The
     user or developer of  performance  utilities  can  use  this
     information to analyze system memory allocations and develop
     a better understanding of the factors affecting  application
     performance.


     The caller of meminfo() can obtain the  following  types  of
     information about both virtual and physical memory.




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System Calls                                           meminfo(2)



     MEMINFO_VPHYSICAL         physical address corresponding  to
                               virtual address


     MEMINFO_VLGRP             locality group  of  physical  page
                               corresponding to virtual address


     MEMINFO_VPAGESIZE         size of physical page  correspond-
                               ing to virtual address


     MEMINFO_VREPLCNT          number  of   replicated   physical
                               pages  corresponding  to specified
                               virtual address


     MEMINFO_VREPL | n         nth physical replica of  specified
                               virtual address


     MEMINFO_VREPL_LGRP | n    lgrp of nth  physical  replica  of
                               specified virtual address


     MEMINFO_PLGRP             locality group of specified physi-
                               cal address


RETURN VALUES
     Upon successful completion meminfo() returns 0. Otherwise -1
     is returned and errno is set to indicate the error.

ERRORS
     The meminfo() function will fail if:

     EFAULT    The area pointed to by outdata or  validity  could
               not be written, or the data pointed to by info_req
               or inaddr could not be read.


     EINVAL    The value of info_count is greater than 31 or less
               than 1, or the value of addr_count is less than 1.


EXAMPLES
     Example 1 Print physical pages and page sizes  corresponding
     to a set of virtual addresses.


     The following example prints the  physical  pages  and  page
     sizes corresponding to a set of virtual addresses.



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System Calls                                           meminfo(2)



       void
       print_info(void **addrvec, int how_many)
       {
           static const uint_t info[] = {
               MEMINFO_VPHYSICAL,
               MEMINFO_VPAGESIZE
           };

           int info_num = sizeof (info) / sizeof (info[0]);
           int i;

           uint64_t *inaddr = alloca(sizeof (uint64_t) * how_many);
           uint64_t *outdata = alloca(sizeof (uint64_t) * how_many * info_num);
           uint_t *validity = alloca(sizeof (uint_t) * how_many);

           for (i = 0; i < how_many; i++)
               inaddr[i] = (uint64_t)addrvec[i];

           if (meminfo(inaddr, how_many, info, info_num, outdata,
                       validity) < 0) {
               perror("meminfo");
               return;
           }

           for (i = 0; i < how_many; i++) {
               if ((validity[i] & 1) == 0)
                   printf("address 0x%llx not part of address space\n",
                       inaddr[i]);

               else if ((validity[i] & 2) == 0)
                   printf("address 0x%llx has no physical page "
                       "associated with it\n", inaddr[i]);

               else {
                   char buff[80];
                   if ((validity[i] & 4) == 0)
                       strcpy(buff, "");
                   else
                       sprintf(buff, "%lld",
                           outdata[i * info_num + 1]);

                   printf("address 0x%llx is backed by physical "
                       "page 0x%llx of size %s\n",
                       inaddr[i], outdata[i * info_num], buff);
               }
           }
       }


ATTRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:



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System Calls                                           meminfo(2)



     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | Interface Stability         | Committed                   |
    |_____________________________|_____________________________|
    | MT-Level                    | Async-Signal-Safe           |
    |_____________________________|_____________________________|


SEE ALSO
     memcntl(2),  mmap(2),  gethomelgroup(3C),   getpagesize(3C),
     madvise(3C), sysconf(3C), attributes(5)











































SunOS 5.11          Last change: 21 Feb 2003                    4