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Diffstat (limited to 'Documentation/filesystems/proc.txt')
| -rw-r--r-- | Documentation/filesystems/proc.txt | 287 |
1 files changed, 228 insertions, 59 deletions
diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt index ce84cfc9eae0..fad18f9456e4 100644 --- a/Documentation/filesystems/proc.txt +++ b/Documentation/filesystems/proc.txt @@ -5,11 +5,12 @@ Bodo Bauer <bb@ricochet.net> 2.4.x update Jorge Nerin <comandante@zaralinux.com> November 14 2000 -move /proc/sys Shen Feng <shen@cn.fujitsu.com> April 1 2009 +move /proc/sys Shen Feng <shen@cn.fujitsu.com> April 1 2009 ------------------------------------------------------------------------------ Version 1.3 Kernel version 2.2.12 Kernel version 2.4.0-test11-pre4 ------------------------------------------------------------------------------ +fixes/update part 1.1 Stefani Seibold <stefani@seibold.net> June 9 2009 Table of Contents ----------------- @@ -116,7 +117,7 @@ The link self points to the process reading the file system. Each process subdirectory has the entries listed in Table 1-1. -Table 1-1: Process specific entries in /proc +Table 1-1: Process specific entries in /proc .............................................................................. File Content clear_refs Clears page referenced bits shown in smaps output @@ -134,46 +135,103 @@ Table 1-1: Process specific entries in /proc status Process status in human readable form wchan If CONFIG_KALLSYMS is set, a pre-decoded wchan stack Report full stack trace, enable via CONFIG_STACKTRACE - smaps Extension based on maps, the rss size for each mapped file + smaps a extension based on maps, showing the memory consumption of + each mapping .............................................................................. For example, to get the status information of a process, all you have to do is read the file /proc/PID/status: - >cat /proc/self/status - Name: cat - State: R (running) - Pid: 5452 - PPid: 743 + >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 - Groups: 100 14 16 - VmSize: 1112 kB - VmLck: 0 kB - VmRSS: 348 kB - VmData: 24 kB - VmStk: 12 kB - VmExe: 8 kB - VmLib: 1044 kB - SigPnd: 0000000000000000 - SigBlk: 0000000000000000 - SigIgn: 0000000000000000 - SigCgt: 0000000000000000 - CapInh: 00000000fffffeff - CapPrm: 0000000000000000 - CapEff: 0000000000000000 - + 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 This shows you nearly the same information you would get if you viewed it with the ps command. In fact, ps uses the proc file system to obtain its -information. The statm file contains more detailed information about the -process memory usage. Its seven fields are explained in Table 1-2. The stat -file contains details information about the process itself. Its fields are -explained in Table 1-3. +information. But you get a more detailed view of the process by reading the +file /proc/PID/status. It fields are described in table 1-2. + +The statm file contains more detailed information about the process +memory usage. Its seven fields are explained in Table 1-3. The stat file +contains details information about the process itself. Its fields are +explained in Table 1-4. +Table 1-2: Contents of the statm files (as of 2.6.30-rc7) +.............................................................................. + Field Content + Name filename of the executable + State state (R is running, S is sleeping, D is sleeping + in an uninterruptible wait, Z is zombie, + T is traced or stopped) + Tgid thread group ID + Pid process id + PPid process id of the parent process + TracerPid PID of process tracing this process (0 if not) + Uid Real, effective, saved set, and file system UIDs + Gid Real, effective, saved set, and file system GIDs + FDSize number of file descriptor slots currently allocated + Groups supplementary group list + VmPeak peak virtual memory size + VmSize total program size + VmLck locked memory size + VmHWM peak resident set size ("high water mark") + VmRSS size of memory portions + VmData size of data, stack, and text segments + VmStk size of data, stack, and text segments + VmExe size of text segment + VmLib size of shared library code + VmPTE size of page table entries + Threads number of threads + SigQ number of signals queued/max. number for queue + SigPnd bitmap of pending signals for the thread + ShdPnd bitmap of shared pending signals for the process + SigBlk bitmap of blocked signals + SigIgn bitmap of ignored signals + SigCgt bitmap of catched signals + CapInh bitmap of inheritable capabilities + CapPrm bitmap of permitted capabilities + CapEff bitmap of effective capabilities + CapBnd bitmap of capabilities bounding set + Cpus_allowed mask of CPUs on which this process may run + Cpus_allowed_list Same as previous, but in "list format" + Mems_allowed mask of memory nodes allowed to this process + Mems_allowed_list Same as previous, but in "list format" + voluntary_ctxt_switches number of voluntary context switches + nonvoluntary_ctxt_switches number of non voluntary context switches +.............................................................................. -Table 1-2: Contents of the statm files (as of 2.6.8-rc3) +Table 1-3: Contents of the statm files (as of 2.6.8-rc3) .............................................................................. Field Content size total program size (pages) (same as VmSize in status) @@ -188,7 +246,7 @@ Table 1-2: Contents of the statm files (as of 2.6.8-rc3) .............................................................................. -Table 1-3: Contents of the stat files (as of 2.6.22-rc3) +Table 1-4: Contents of the stat files (as of 2.6.30-rc7) .............................................................................. Field Content pid process id @@ -222,10 +280,10 @@ Table 1-3: Contents of the stat files (as of 2.6.22-rc3) start_stack address of the start of the stack esp current value of ESP eip current value of EIP - pending bitmap of pending signals (obsolete) - blocked bitmap of blocked signals (obsolete) - sigign bitmap of ignored signals (obsolete) - sigcatch bitmap of catched signals (obsolete) + pending bitmap of pending signals + blocked bitmap of blocked signals + sigign bitmap of ignored signals + sigcatch bitmap of catched signals wchan address where process went to sleep 0 (place holder) 0 (place holder) @@ -234,19 +292,99 @@ Table 1-3: Contents of the stat files (as of 2.6.22-rc3) rt_priority realtime priority policy scheduling policy (man sched_setscheduler) blkio_ticks time spent waiting for block IO + gtime guest time of the task in jiffies + cgtime guest time of the task children in jiffies .............................................................................. +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 +0804a000-0806b000 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. + + +The /proc/PID/smaps is an extension based on maps, showing the memory +consumption for each of the process's mappings. For each of mappings there +is a series of lines such as the following: + +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 + +The first of these lines shows the same information as is displayed for the +mapping in /proc/PID/maps. The remaining lines show the size of the mapping, +the amount of the mapping that is currently resident in RAM, the "proportional +set size” (divide each shared page by the number of processes sharing it), the +number of clean and dirty shared pages in the mapping, and the number of clean +and dirty private pages in the mapping. The "Referenced" indicates the amount +of memory currently marked as referenced or accessed. + +This file is only present if the CONFIG_MMU kernel configuration option is +enabled. 1.2 Kernel data --------------- Similar to the process entries, the kernel data files give information about the running kernel. The files used to obtain this information are contained in -/proc and are listed in Table 1-4. Not all of these will be present in your +/proc and are listed in Table 1-5. Not all of these will be present in your system. It depends on the kernel configuration and the loaded modules, which files are there, and which are missing. -Table 1-4: Kernel info in /proc +Table 1-5: Kernel info in /proc .............................................................................. File Content apm Advanced power management info @@ -283,6 +421,7 @@ Table 1-4: Kernel info in /proc rtc Real time clock scsi SCSI info (see text) slabinfo Slab pool info + softirqs softirq usage stat Overall statistics swaps Swap space utilization sys See chapter 2 @@ -366,7 +505,7 @@ just those considered 'most important'. The new vectors are: RES, CAL, TLB -- rescheduling, call and TLB flush interrupts are sent from one CPU to another per the needs of the OS. Typically, their statistics are used by kernel developers and interested users to - determine the occurance of interrupt of the given type. + determine the occurrence of interrupts of the given type. The above IRQ vectors are displayed only when relevent. For example, the threshold vector does not exist on x86_64 platforms. Others are @@ -551,7 +690,7 @@ Committed_AS: The amount of memory presently allocated on the system. memory once that memory has been successfully allocated. VmallocTotal: total size of vmalloc memory area VmallocUsed: amount of vmalloc area which is used -VmallocChunk: largest contigious block of vmalloc area which is free +VmallocChunk: largest contiguous block of vmalloc area which is free .............................................................................. @@ -597,6 +736,25 @@ on the kind of area : 0xffffffffa0017000-0xffffffffa0022000 45056 sys_init_module+0xc27/0x1d00 ... pages=10 vmalloc N0=10 +.............................................................................. + +softirqs: + +Provides counts of softirq handlers serviced since boot time, for each cpu. + +> cat /proc/softirqs + CPU0 CPU1 CPU2 CPU3 + HI: 0 0 0 0 + TIMER: 27166 27120 27097 27034 + NET_TX: 0 0 0 17 + NET_RX: 42 0 0 39 + BLOCK: 0 0 107 1121 + TASKLET: 0 0 0 290 + SCHED: 27035 26983 26971 26746 + HRTIMER: 0 0 0 0 + RCU: 1678 1769 2178 2250 + + 1.3 IDE devices in /proc/ide ---------------------------- @@ -614,10 +772,10 @@ IDE devices: More detailed information can be found in the controller specific subdirectories. These are named ide0, ide1 and so on. Each of these -directories contains the files shown in table 1-5. +directories contains the files shown in table 1-6. -Table 1-5: IDE controller info in /proc/ide/ide? +Table 1-6: IDE controller info in /proc/ide/ide? .............................................................................. File Content channel IDE channel (0 or 1) @@ -627,11 +785,11 @@ Table 1-5: IDE controller info in /proc/ide/ide? .............................................................................. Each device connected to a controller has a separate subdirectory in the -controllers directory. The files listed in table 1-6 are contained in these +controllers directory. The files listed in table 1-7 are contained in these directories. -Table 1-6: IDE device information +Table 1-7: IDE device information .............................................................................. File Content cache The cache @@ -673,12 +831,12 @@ the drive parameters: 1.4 Networking info in /proc/net -------------------------------- -The subdirectory /proc/net follows the usual pattern. Table 1-6 shows the +The subdirectory /proc/net follows the usual pattern. Table 1-8 shows the additional values you get for IP version 6 if you configure the kernel to -support this. Table 1-7 lists the files and their meaning. +support this. Table 1-9 lists the files and their meaning. -Table 1-6: IPv6 info in /proc/net +Table 1-8: IPv6 info in /proc/net .............................................................................. File Content udp6 UDP sockets (IPv6) @@ -693,7 +851,7 @@ Table 1-6: IPv6 info in /proc/net .............................................................................. -Table 1-7: Network info in /proc/net +Table 1-9: Network info in /proc/net .............................................................................. File Content arp Kernel ARP table @@ -817,10 +975,10 @@ The directory /proc/parport contains information about the parallel ports of your system. It has one subdirectory for each port, named after the port number (0,1,2,...). -These directories contain the four files shown in Table 1-8. +These directories contain the four files shown in Table 1-10. -Table 1-8: Files in /proc/parport +Table 1-10: Files in /proc/parport .............................................................................. File Content autoprobe Any IEEE-1284 device ID information that has been acquired. @@ -838,10 +996,10 @@ Table 1-8: Files in /proc/parport Information about the available and actually used tty's can be found in the directory /proc/tty.You'll find entries for drivers and line disciplines in -this directory, as shown in Table 1-9. +this directory, as shown in Table 1-11. -Table 1-9: Files in /proc/tty +Table 1-11: Files in /proc/tty .............................................................................. File Content drivers list of drivers and their usage @@ -883,6 +1041,7 @@ since the system first booted. For a quick look, simply cat the file: processes 2915 procs_running 1 procs_blocked 0 + softirq 183433 0 21755 12 39 1137 231 21459 2263 The very first "cpu" line aggregates the numbers in all of the other "cpuN" lines. These numbers identify the amount of time the CPU has spent performing @@ -918,6 +1077,11 @@ CPUs. The "procs_blocked" line gives the number of processes currently blocked, waiting for I/O to complete. +The "softirq" line gives counts of softirqs serviced since boot time, for each +of the possible system softirqs. The first column is the total of all +softirqs serviced; each subsequent column is the total for that particular +softirq. + 1.9 Ext4 file system parameters ------------------------------ @@ -926,9 +1090,9 @@ Information about mounted ext4 file systems can be found in /proc/fs/ext4. Each mounted filesystem will have a directory in /proc/fs/ext4 based on its device name (i.e., /proc/fs/ext4/hdc or /proc/fs/ext4/dm-0). The files in each per-device directory are shown -in Table 1-10, below. +in Table 1-12, below. -Table 1-10: Files in /proc/fs/ext4/<devname> +Table 1-12: Files in /proc/fs/ext4/<devname> .............................................................................. File Content mb_groups details of multiblock allocator buddy cache of free blocks @@ -1003,11 +1167,13 @@ CHAPTER 3: PER-PROCESS PARAMETERS 3.1 /proc/<pid>/oom_adj - Adjust the oom-killer score ------------------------------------------------------ -This file can be used to adjust the score used to select which processes -should be killed in an out-of-memory situation. Giving it a high score will -increase the likelihood of this process being killed by the oom-killer. Valid -values are in the range -16 to +15, plus the special value -17, which disables -oom-killing altogether for this process. +This file can be used to adjust the score used to select which processes should +be killed in an out-of-memory situation. The oom_adj value is a characteristic +of the task's mm, so all threads that share an mm with pid will have the same +oom_adj value. A high value will increase the likelihood of this process being +killed by the oom-killer. Valid values are in the range -16 to +15 as +explained below and a special value of -17, which disables oom-killing +altogether for threads sharing pid's mm. The process to be killed in an out-of-memory situation is selected among all others based on its badness score. This value equals the original memory size of the process @@ -1021,6 +1187,9 @@ the parent's score if they do not share the same memory. Thus forking servers are the prime candidates to be killed. Having only one 'hungry' child will make parent less preferable than the child. +/proc/<pid>/oom_adj cannot be changed for kthreads since they are immune from +oom-killing already. + /proc/<pid>/oom_score shows process' current badness score. The following heuristics are then applied: |