diff options
Diffstat (limited to 'Documentation/filesystems/proc.txt')
| -rw-r--r-- | Documentation/filesystems/proc.txt | 74 |
1 files changed, 66 insertions, 8 deletions
diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt index b5aee7838a0..a4f30faa4f1 100644 --- a/Documentation/filesystems/proc.txt +++ b/Documentation/filesystems/proc.txt @@ -38,6 +38,7 @@ Table of Contents 3.3 /proc/<pid>/io - Display the IO accounting fields 3.4 /proc/<pid>/coredump_filter - Core dump filtering settings 3.5 /proc/<pid>/mountinfo - Information about mounts + 3.6 /proc/<pid>/comm & /proc/<pid>/task/<tid>/comm ------------------------------------------------------------------------------ @@ -163,6 +164,7 @@ read the file /proc/PID/status: VmExe: 68 kB VmLib: 1412 kB VmPTE: 20 kb + VmSwap: 0 kB Threads: 1 SigQ: 0/28578 SigPnd: 0000000000000000 @@ -176,7 +178,6 @@ read the file /proc/PID/status: CapBnd: ffffffffffffffff voluntary_ctxt_switches: 0 nonvoluntary_ctxt_switches: 1 - Stack usage: 12 kB 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 @@ -188,7 +189,13 @@ 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) +(for SMP CONFIG users) +For making accounting scalable, RSS related information are handled in +asynchronous manner and the vaule may not be very precise. To see a precise +snapshot of a moment, you can see /proc/<pid>/smaps file and scan page table. +It's slow but very precise. + +Table 1-2: Contents of the status files (as of 2.6.30-rc7) .............................................................................. Field Content Name filename of the executable @@ -213,6 +220,7 @@ Table 1-2: Contents of the statm files (as of 2.6.30-rc7) VmExe size of text segment VmLib size of shared library code VmPTE size of page table entries + VmSwap size of swap usage (the number of referred swapents) Threads number of threads SigQ number of signals queued/max. number for queue SigPnd bitmap of pending signals for the thread @@ -230,7 +238,6 @@ Table 1-2: Contents of the statm files (as of 2.6.30-rc7) 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 - Stack usage: stack usage high water mark (round up to page size) .............................................................................. Table 1-3: Contents of the statm files (as of 2.6.8-rc3) @@ -431,6 +438,7 @@ Table 1-5: Kernel info in /proc modules List of loaded modules mounts Mounted filesystems net Networking info (see text) + pagetypeinfo Additional page allocator information (see text) (2.5) partitions Table of partitions known to the system pci Deprecated info of PCI bus (new way -> /proc/bus/pci/, decoupled by lspci (2.4) @@ -585,7 +593,7 @@ Node 0, zone DMA 0 4 5 4 4 3 ... Node 0, zone Normal 1 0 0 1 101 8 ... Node 0, zone HighMem 2 0 0 1 1 0 ... -Memory fragmentation is a problem under some workloads, and buddyinfo is a +External fragmentation is a problem under some workloads, and buddyinfo is a useful tool for helping diagnose these problems. Buddyinfo will give you a clue as to how big an area you can safely allocate, or why a previous allocation failed. @@ -595,6 +603,48 @@ available. In this case, there are 0 chunks of 2^0*PAGE_SIZE available in ZONE_DMA, 4 chunks of 2^1*PAGE_SIZE in ZONE_DMA, 101 chunks of 2^4*PAGE_SIZE available in ZONE_NORMAL, etc... +More information relevant to external fragmentation can be found in +pagetypeinfo. + +> cat /proc/pagetypeinfo +Page block order: 9 +Pages per block: 512 + +Free pages count per migrate type at order 0 1 2 3 4 5 6 7 8 9 10 +Node 0, zone DMA, type Unmovable 0 0 0 1 1 1 1 1 1 1 0 +Node 0, zone DMA, type Reclaimable 0 0 0 0 0 0 0 0 0 0 0 +Node 0, zone DMA, type Movable 1 1 2 1 2 1 1 0 1 0 2 +Node 0, zone DMA, type Reserve 0 0 0 0 0 0 0 0 0 1 0 +Node 0, zone DMA, type Isolate 0 0 0 0 0 0 0 0 0 0 0 +Node 0, zone DMA32, type Unmovable 103 54 77 1 1 1 11 8 7 1 9 +Node 0, zone DMA32, type Reclaimable 0 0 2 1 0 0 0 0 1 0 0 +Node 0, zone DMA32, type Movable 169 152 113 91 77 54 39 13 6 1 452 +Node 0, zone DMA32, type Reserve 1 2 2 2 2 0 1 1 1 1 0 +Node 0, zone DMA32, type Isolate 0 0 0 0 0 0 0 0 0 0 0 + +Number of blocks type Unmovable Reclaimable Movable Reserve Isolate +Node 0, zone DMA 2 0 5 1 0 +Node 0, zone DMA32 41 6 967 2 0 + +Fragmentation avoidance in the kernel works by grouping pages of different +migrate types into the same contiguous regions of memory called page blocks. +A page block is typically the size of the default hugepage size e.g. 2MB on +X86-64. By keeping pages grouped based on their ability to move, the kernel +can reclaim pages within a page block to satisfy a high-order allocation. + +The pagetypinfo begins with information on the size of a page block. It +then gives the same type of information as buddyinfo except broken down +by migrate-type and finishes with details on how many page blocks of each +type exist. + +If min_free_kbytes has been tuned correctly (recommendations made by hugeadm +from libhugetlbfs http://sourceforge.net/projects/libhugetlbfs/), one can +make an estimate of the likely number of huge pages that can be allocated +at a given point in time. All the "Movable" blocks should be allocatable +unless memory has been mlock()'d. Some of the Reclaimable blocks should +also be allocatable although a lot of filesystem metadata may have to be +reclaimed to achieve this. + .............................................................................. meminfo: @@ -1072,7 +1122,8 @@ second). The meanings of the columns are as follows, from left to right: - irq: servicing interrupts - softirq: servicing softirqs - steal: involuntary wait -- guest: running a guest +- guest: running a normal guest +- guest_nice: running a niced guest The "intr" line gives counts of interrupts serviced since boot time, for each of the possible system interrupts. The first column is the total of all @@ -1088,8 +1139,8 @@ The "processes" line gives the number of processes and threads created, which includes (but is not limited to) those created by calls to the fork() and clone() system calls. -The "procs_running" line gives the number of processes currently running on -CPUs. +The "procs_running" line gives the total number of threads that are +running or ready to run (i.e., the total number of runnable threads). The "procs_blocked" line gives the number of processes currently blocked, waiting for I/O to complete. @@ -1113,7 +1164,6 @@ Table 1-12: Files in /proc/fs/ext4/<devname> .............................................................................. File Content mb_groups details of multiblock allocator buddy cache of free blocks - mb_history multiblock allocation history .............................................................................. @@ -1409,3 +1459,11 @@ For more information on mount propagation see: Documentation/filesystems/sharedsubtree.txt + +3.6 /proc/<pid>/comm & /proc/<pid>/task/<tid>/comm +-------------------------------------------------------- +These files provide a method to access a tasks comm value. It also allows for +a task to set its own or one of its thread siblings comm value. The comm value +is limited in size compared to the cmdline value, so writing anything longer +then the kernel's TASK_COMM_LEN (currently 16 chars) will result in a truncated +comm value. |