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--- etc:users:jcmvbkbc:linux-mm [2009/07/13 18:23] – jcmvbkbc
+++ etc:users:jcmvbkbc:linux-mm [2016/08/08 20:53] (current) – ↷ Page moved from users:jcmvbkbc:linux-mm to etc:users:jcmvbkbc:linux-mm kel
@@ Line 1: / Line 1: @@
 ====== Linux memory management summary ======
 Every part of process address space is some sort of mapping.
@@ Line 29: / Line 30: @@
   * swap -- size of region data that is currently in swap file;
-  * Charging memory to processes
-  * total_vm
 ==== Information sources ====
+Quotes from linux/Documentation/filesystems/proc.txt
 Per-process data:
-  * /proc/<PID>/maps -- process memory map;
+  * /proc/<PID>/map -- process memory map;
+<code>
+The /proc/PID/map file containing the currently mapped memory regions and
+their access permissions.
+The format is:
+address           perms offset  dev   inode      pathname
+08048000-08049000 r-xp 00000000 03:00 8312       /opt/test
+08049000-0804a000 rw-p 00001000 03:00 8312       /opt/test
+a000-0806b000 rw-p 00000000 00:00 0          [heap]
+a7cb1000-a7cb2000 ---p 00000000 00:00 0
+a7cb2000-a7eb2000 rw-p 00000000 00:00 0
+a7eb2000-a7eb3000 ---p 00000000 00:00 0
+a7eb3000-a7ed5000 rw-p 00000000 00:00 0
+a7ed5000-a8008000 r-xp 00000000 03:00 4222       /lib/libc.so.6
+a8008000-a800a000 r--p 00133000 03:00 4222       /lib/libc.so.6
+a800a000-a800b000 rw-p 00135000 03:00 4222       /lib/libc.so.6
+a800b000-a800e000 rw-p 00000000 00:00 0
+a800e000-a8022000 r-xp 00000000 03:00 14462      /lib/libpthread.so.0
+a8022000-a8023000 r--p 00013000 03:00 14462      /lib/libpthread.so.0
+a8023000-a8024000 rw-p 00014000 03:00 14462      /lib/libpthread.so.0
+a8024000-a8027000 rw-p 00000000 00:00 0
+a8027000-a8043000 r-xp 00000000 03:00 8317       /lib/ld-linux.so.2
+a8043000-a8044000 r--p 0001b000 03:00 8317       /lib/ld-linux.so.2
+a8044000-a8045000 rw-p 0001c000 03:00 8317       /lib/ld-linux.so.2
+aff35000-aff4a000 rw-p 00000000 00:00 0          [stack]
+ffffe000-fffff000 r-xp 00000000 00:00 0          [vdso]
+where "address" is the address space in the process that it occupies, "perms"
+is a set of permissions:
+ r = read
+ w = write
+ x = execute
+ s = shared
+ p = private (copy on write)
+"offset" is the offset into the mapping, "dev" is the device (major:minor), and
+"inode" is the inode  on that device.  0 indicates that  no inode is associated
+with the memory region, as the case would be with BSS (uninitialized data).
+The "pathname" shows the name associated file for this mapping.  If the mapping
+is not associated with a file:
+ [heap]                   = the heap of the program
+ [stack]                  = the stack of the main process
+ [vdso]                   = the "virtual dynamic shared object",
+                            the kernel system call handler
+ or if empty, the mapping is anonymous.
+</code>
   * /proc/<PID>/smaps -- detailed process memory map;
+<code>
+08048000-080bc000 r-xp 00000000 03:02 13130      /bin/bash
+Size:               1084 kB
+Rss:                 892 kB
+Pss:                 374 kB
+Shared_Clean:        892 kB
+Shared_Dirty:          0 kB
+Private_Clean:         0 kB
+Private_Dirty:         0 kB
+Referenced:          892 kB
+Swap:                  0 kB
+KernelPageSize:        4 kB
+MMUPageSize:           4 kB
+</code>
   * /proc/<PID>/statm -- process memory usage summary;
+<code>
+ Field    Content
+ size     total program size (pages)            (same as VmSize in status)
+ resident size of memory portions (pages)       (same as VmRSS in status)
+ shared   number of pages that are shared       (i.e. backed by a file)
+ trs      number of pages that are 'code'       (not including libs; broken,
+                                                        includes data segment)
+ lrs      number of pages of library            (always 0 on 2.6)
+ drs      number of pages of data/stack         (including libs; broken,
+                                                        includes library text)
+ dt       number of dirty pages                 (always 0 on 2.6)
+</code>
   * /proc/<PID>/status -- process status;
+<code>
+  >cat /proc/self/status
+  Name:   cat
+  State:  R (running)
+  Tgid:   5452
+  Pid:    5452
+  PPid:   743
+  TracerPid:      0                                             (2.4)
+  Uid:    501     501     501     501
+  Gid:    100     100     100     100
+  FDSize: 256
+  Groups: 100 14 16
+  VmPeak:     5004 kB
+  VmSize:     5004 kB
+  VmLck:         0 kB
+  VmHWM:       476 kB
+  VmRSS:       476 kB
+  VmData:      156 kB
+  VmStk:        88 kB
+  VmExe:        68 kB
+  VmLib:      1412 kB
+  VmPTE:        20 kb
+  Threads:        1
+  SigQ:   0/28578
+  SigPnd: 0000000000000000
+  ShdPnd: 0000000000000000
+  SigBlk: 0000000000000000
+  SigIgn: 0000000000000000
+  SigCgt: 0000000000000000
+  CapInh: 00000000fffffeff
+  CapPrm: 0000000000000000
+  CapEff: 0000000000000000
+  CapBnd: ffffffffffffffff
+  voluntary_ctxt_switches:        0
+  nonvoluntary_ctxt_switches:     1
+</code>
   * /proc/<PID>/oom_adj
   * /proc/<PID>/oom_score
@@ Line 120: / Line 234: @@
     * if (oom_adj > 0) points <<= oom_adj; //(if points == 0 before shift, points = 1)//
     * if (oom_adj < 0) points >>= -oom_adj;
@@ Line 128: / Line 243: @@
   * vm.panic_on_oom -- panic in case of OOM, instead of trying to kill some processes;
   * vm.oom_kill_allocating_task -- try first to kill task that issued request for memory that caused OOM condition;
-  * vm.oom_dump_tasks -- dump memory summary, stack of the process caused oom and table of processes to log at before oom-killing;
+  * vm.oom_dump_tasks -- dump memory summary, stack of the process caused oom and table of processes to log before oom-killing;
   * vm.would_have_oomkilled