pfiles in zone

open-5k.c

#include <fcntl.h>
#include <stdio.h>

#define FILE_TO_OPEN "/etc/passwd"
#define TIMES 5000

int main() {
        int fd;
        int i;
        printf("pid: %d\n", getpid());
        for (i = 0; i < TIMES; i++) {
                if (fd = open(FILE_TO_OPEN, O_RDONLY) == -1) {
                        perror("open");
                        return 1;
                }
        }
        sleep(300);
        return 0;
}

output.txt

dave - sjc1-dave-01 sunos ~ $ ./open-5k &
[1] 32690
pid: 32690
dave - sjc1-dave-01 sunos ~ $ sudo dtrace -n 'syscall:::entry /pid == $target/ { @[probefunc]=count(); }' -c "sudo pfiles 32690"
dtrace: description 'syscall:::entry ' matched 233 probes
...
(pfiles output)
  forksys                                                           1
  getcwd                                                            1
  pipe                                                              1
  putmsg                                                            1
  recv                                                              1
  schedctl                                                          1
  setrlimit                                                         1
  sigpending                                                        1
  so_socketpair                                                     1
  sysi86                                                            1
  waitsys                                                           1
  write                                                             1
  getrlimit                                                         2
  gtime                                                             2
  munmap                                                            2
  privsys                                                           2
  setpgrp                                                           2
  systeminfo                                                        2
  lwp_sigmask                                                       3
  pollsys                                                           3
  setcontext                                                        3
  so_socket                                                         3
  getgroups                                                         4
  setgroups                                                         4
  setuid                                                            4
  sysconfig                                                         4
  setregid                                                          8
  setreuid                                                          8
  getpid                                                            9
  fcntl                                                            10
  lseek                                                            10
  priocntlsys                                                      11
  ioctl                                                            12
  brk                                                              15
  doorfs                                                           18
  getuid                                                           20
  fstat                                                            23
  sigaction                                                        33
  memcntl                                                          36
  mmapobj                                                          39
  resolvepath                                                      39
  lwp_cond_broadcast                                               40
  read                                                             43
  mmap                                                             51
  close                                                            62
  open                                                             65
  stat                                                             87

z-open-5k-sockets.js

#!/usr/bin/env node
var net = require('net');

for (var i = 0; i < 5000; i++)
  net.connect(80, 'daveeddy.com');

z-output.txt

dave - sjc1-dave-01 sunos ~ $ ./open-5k-sockets.js &
[1] 34728
dave - sjc1-dave-01 sunos ~ $ sudo ptime pfiles 34728
34728:  node ./open-5k-sockets.js

real     1:28.918439782
user        0.695646071
sys      1:26.230105158

  8  14722                   readlink:entry 
              libc.so.1`__systemcall6+0x1e
              libproc.so.1`load_fdinfo+0x17c
              libproc.so.1`Pfdinfo_iter+0x32
              pfiles`show_files+0x4b
              pfiles`main+0x1b6
              pfiles`_start+0x6c

http://src.illumos.org/source/xref/illumos-gate/usr/src/lib/libproc/common/Pfdinfo.c#139

Cut 1k open files down to 4 seconds by LD_PRELOADing a readlink that does nothing

#include <stdlib.h>
#include <errno.h>
size_t readlink(const char *path, char *buf, size_t bufsize) {
        errno = ENOSYS;
        return -1;
}

$ cc -shared -fPIC -o readlink.so readlink.c
$ node open-1k-sockets.js &
[1] 88758
$ LD_PRELOAD=./readlink.so /usr/bin/amd64/ptime /usr/bin/amd64/pfiles 88758
... 1000 open sockets ...

real        4.061913621
user        0.354056032
sys         2.692370925

diff --git a/usr/src/lib/libproc/common/Pfdinfo.c b/usr/src/lib/libproc/common/Pfdinfo.c
index 1244397..b5e4d83 100644
--- a/usr/src/lib/libproc/common/Pfdinfo.c
+++ b/usr/src/lib/libproc/common/Pfdinfo.c
@@ -134,10 +134,17 @@ load_fdinfo(struct ps_prochandle *P)
                        info->pr_offset = pr_llseek(P, fd, 0, SEEK_CUR);

                        /* attempt to determine the path to it */
-                       (void) snprintf(path, sizeof (path),
-                           "%s/%d/path/%d", procfs_path, (int)P->pid, fd);
-                       len = readlink(path, info->pr_path,
-                           sizeof (info->pr_path) - 1);
+                       switch (info->pr_mode & S_IFMT) {
+                       case S_IFSOCK: case S_IFDOOR: /* not applicable */
+                               len = -1;
+                               break;
+                       default:
+                               (void) snprintf(path, sizeof (path),
+                                   "%s/%d/path/%d", procfs_path, (int)P->pid, fd);
+                               len = readlink(path, info->pr_path,
+                                   sizeof (info->pr_path) - 1);
+                               break;
+                       }

                        if (len < 0) {
                                info->pr_path[0] = 0;

without LD_PRELOAD

dave - sjc1-dave-01 sunos ~/pfiles $ ./open-sockets.js &
[1] 75375
dave - sjc1-dave-01 sunos ~/pfiles $ opened 1000 sockets
ptime pfiles 75375 > /dev/null

real       45.522214487
user        0.334410765
sys        44.691393983

with LD_PRELOAD

dave - sjc1-dave-01 sunos ~/pfiles $ ./open-sockets.js &
[1] 75690
dave - sjc1-dave-01 sunos ~/pfiles $ opened 1000 sockets
LD_PRELOAD=./readlink.so /usr/bin/amd64/ptime /usr/bin/amd64/pfiles 75690 > /dev/null

real        3.887839734
user        0.328562456
sys         2.558752763