2.13 /proc/<pid>/oom_score - Display current oom-killer score
2.14 /proc/<pid>/io - Display the IO accounting fields
2.15 /proc/<pid>/coredump_filter - Core dump filtering settings
+ 2.16 /proc/<pid>/mountinfo - Information about mounts
------------------------------------------------------------------------------
Preface
priority priority level
nice nice level
num_threads number of threads
+ it_real_value (obsolete, always 0)
start_time time the process started after system boot
vsize virtual memory size
rss resident set memory size
SwapFree: 0 kB
Dirty: 968 kB
Writeback: 0 kB
+AnonPages: 861800 kB
Mapped: 280372 kB
-Slab: 684068 kB
+Slab: 284364 kB
+SReclaimable: 159856 kB
+SUnreclaim: 124508 kB
+PageTables: 24448 kB
+NFS_Unstable: 0 kB
+Bounce: 0 kB
+WritebackTmp: 0 kB
CommitLimit: 7669796 kB
Committed_AS: 100056 kB
-PageTables: 24448 kB
VmallocTotal: 112216 kB
VmallocUsed: 428 kB
VmallocChunk: 111088 kB
on the disk
Dirty: Memory which is waiting to get written back to the disk
Writeback: Memory which is actively being written back to the disk
+ AnonPages: Non-file backed pages mapped into userspace page tables
Mapped: files which have been mmaped, such as libraries
Slab: in-kernel data structures cache
+SReclaimable: Part of Slab, that might be reclaimed, such as caches
+ SUnreclaim: Part of Slab, that cannot be reclaimed on memory pressure
+ PageTables: amount of memory dedicated to the lowest level of page
+ tables.
+NFS_Unstable: NFS pages sent to the server, but not yet committed to stable
+ storage
+ Bounce: Memory used for block device "bounce buffers"
+WritebackTmp: Memory used by FUSE for temporary writeback buffers
CommitLimit: Based on the overcommit ratio ('vm.overcommit_ratio'),
this is the total amount of memory currently available to
be allocated on the system. This limit is only adhered to
above) will not be permitted. This is useful if one needs
to guarantee that processes will not fail due to lack of
memory once that memory has been successfully allocated.
- PageTables: amount of memory dedicated to the lowest level of page
- tables.
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
The "procs_blocked" line gives the number of processes currently blocked,
waiting for I/O to complete.
+1.9 Ext4 file system parameters
+------------------------------
+Ext4 file system have one directory per partition under /proc/fs/ext4/
+# ls /proc/fs/ext4/hdc/
+group_prealloc max_to_scan mb_groups mb_history min_to_scan order2_req
+stats stream_req
+
+mb_groups:
+This file gives the details of mutiblock allocator buddy cache of free blocks
+
+mb_history:
+Multiblock allocation history.
+
+stats:
+This file indicate whether the multiblock allocator should start collecting
+statistics. The statistics are shown during unmount
+
+group_prealloc:
+The multiblock allocator normalize the block allocation request to
+group_prealloc filesystem blocks if we don't have strip value set.
+The stripe value can be specified at mount time or during mke2fs.
+
+max_to_scan:
+How long multiblock allocator can look for a best extent (in found extents)
+
+min_to_scan:
+How long multiblock allocator must look for a best extent
+
+order2_req:
+Multiblock allocator use 2^N search using buddies only for requests greater
+than or equal to order2_req. The request size is specfied in file system
+blocks. A value of 2 indicate only if the requests are greater than or equal
+to 4 blocks.
+
+stream_req:
+Files smaller than stream_req are served by the stream allocator, whose
+purpose is to pack requests as close each to other as possible to
+produce smooth I/O traffic. Avalue of 16 indicate that file smaller than 16
+filesystem block size will use group based preallocation.
------------------------------------------------------------------------------
Summary
Denotes the number of inodes the system has allocated. This number will
grow and shrink dynamically.
+nr_open
+-------
+
+Denotes the maximum number of file-handles a process can
+allocate. Default value is 1024*1024 (1048576) which should be
+enough for most machines. Actual limit depends on RLIMIT_NOFILE
+resource limit.
+
nr_free_inodes
--------------
resume it if we have a value of 3 or more percent; consider information about
the amount of free space valid for 30 seconds
-audit_argv_kb
--------------
-
-The file contains a single value denoting the limit on the argv array size
-for execve (in KiB). This limit is only applied when system call auditing for
-execve is enabled, otherwise the value is ignored.
-
ctrl-alt-del
------------
Data which has been dirty in-memory for longer than this interval will be
written out next time a pdflush daemon wakes up.
+highmem_is_dirtyable
+--------------------
+
+Only present if CONFIG_HIGHMEM is set.
+
+This defaults to 0 (false), meaning that the ratios set above are calculated
+as a percentage of lowmem only. This protects against excessive scanning
+in page reclaim, swapping and general VM distress.
+
+Setting this to 1 can be useful on 32 bit machines where you want to make
+random changes within an MMAPed file that is larger than your available
+lowmem without causing large quantities of random IO. Is is safe if the
+behavior of all programs running on the machine is known and memory will
+not be otherwise stressed.
+
legacy_va_layout
----------------
If non-zero, this sysctl disables the new 32-bit mmap mmap layout - the kernel
will use the legacy (2.4) layout for all processes.
-lower_zone_protection
+lowmem_reserve_ratio
---------------------
For some specialised workloads on highmem machines it is dangerous for
mechanism will also defend that region from allocations which could use
highmem or lowmem).
-The `lower_zone_protection' tunable determines how aggressive the kernel is
-in defending these lower zones. The default value is zero - no
-protection at all.
+The `lowmem_reserve_ratio' tunable determines how aggressive the kernel is
+in defending these lower zones.
If you have a machine which uses highmem or ISA DMA and your
applications are using mlock(), or if you are running with no swap then
-you probably should increase the lower_zone_protection setting.
-
-The units of this tunable are fairly vague. It is approximately equal
-to "megabytes," so setting lower_zone_protection=100 will protect around 100
-megabytes of the lowmem zone from user allocations. It will also make
-those 100 megabytes unavailable for use by applications and by
-pagecache, so there is a cost.
-
-The effects of this tunable may be observed by monitoring
-/proc/meminfo:LowFree. Write a single huge file and observe the point
-at which LowFree ceases to fall.
-
-A reasonable value for lower_zone_protection is 100.
+you probably should change the lowmem_reserve_ratio setting.
+
+The lowmem_reserve_ratio is an array. You can see them by reading this file.
+-
+% cat /proc/sys/vm/lowmem_reserve_ratio
+256 256 32
+-
+Note: # of this elements is one fewer than number of zones. Because the highest
+ zone's value is not necessary for following calculation.
+
+But, these values are not used directly. The kernel calculates # of protection
+pages for each zones from them. These are shown as array of protection pages
+in /proc/zoneinfo like followings. (This is an example of x86-64 box).
+Each zone has an array of protection pages like this.
+
+-
+Node 0, zone DMA
+ pages free 1355
+ min 3
+ low 3
+ high 4
+ :
+ :
+ numa_other 0
+ protection: (0, 2004, 2004, 2004)
+ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ pagesets
+ cpu: 0 pcp: 0
+ :
+-
+These protections are added to score to judge whether this zone should be used
+for page allocation or should be reclaimed.
+
+In this example, if normal pages (index=2) are required to this DMA zone and
+pages_high is used for watermark, the kernel judges this zone should not be
+used because pages_free(1355) is smaller than watermark + protection[2]
+(4 + 2004 = 2008). If this protection value is 0, this zone would be used for
+normal page requirement. If requirement is DMA zone(index=0), protection[0]
+(=0) is used.
+
+zone[i]'s protection[j] is calculated by following exprssion.
+
+(i < j):
+ zone[i]->protection[j]
+ = (total sums of present_pages from zone[i+1] to zone[j] on the node)
+ / lowmem_reserve_ratio[i];
+(i = j):
+ (should not be protected. = 0;
+(i > j):
+ (not necessary, but looks 0)
+
+The default values of lowmem_reserve_ratio[i] are
+ 256 (if zone[i] means DMA or DMA32 zone)
+ 32 (others).
+As above expression, they are reciprocal number of ratio.
+256 means 1/256. # of protection pages becomes about "0.39%" of total present
+pages of higher zones on the node.
+
+If you would like to protect more pages, smaller values are effective.
+The minimum value is 1 (1/1 -> 100%).
page-cluster
------------
-----------
laptop_mode is a knob that controls "laptop mode". All the things that are
-controlled by this knob are discussed in Documentation/laptop-mode.txt.
+controlled by this knob are discussed in Documentation/laptops/laptop-mode.txt.
block_dump
----------
block_dump enables block I/O debugging when set to a nonzero value. More
-information on block I/O debugging is in Documentation/laptop-mode.txt.
+information on block I/O debugging is in Documentation/laptops/laptop-mode.txt.
swap_token_timeout
------------------
Maximum size of the routing cache. Old entries will be purged once the cache
reached has this size.
-max_delay, min_delay
---------------------
-
-Delays for flushing the routing cache.
-
redirect_load, redirect_number
------------------------------
$ echo 0x7 > /proc/self/coredump_filter
$ ./some_program
+2.16 /proc/<pid>/mountinfo - Information about mounts
+--------------------------------------------------------
+
+This file contains lines of the form:
+
+36 35 98:0 /mnt1 /mnt2 rw,noatime master:1 - ext3 /dev/root rw,errors=continue
+(1)(2)(3) (4) (5) (6) (7) (8) (9) (10) (11)
+
+(1) mount ID: unique identifier of the mount (may be reused after umount)
+(2) parent ID: ID of parent (or of self for the top of the mount tree)
+(3) major:minor: value of st_dev for files on filesystem
+(4) root: root of the mount within the filesystem
+(5) mount point: mount point relative to the process's root
+(6) mount options: per mount options
+(7) optional fields: zero or more fields of the form "tag[:value]"
+(8) separator: marks the end of the optional fields
+(9) filesystem type: name of filesystem of the form "type[.subtype]"
+(10) mount source: filesystem specific information or "none"
+(11) super options: per super block options
+
+Parsers should ignore all unrecognised optional fields. Currently the
+possible optional fields are:
+
+shared:X mount is shared in peer group X
+master:X mount is slave to peer group X
+propagate_from:X mount is slave and receives propagation from peer group X (*)
+unbindable mount is unbindable
+
+(*) X is the closest dominant peer group under the process's root. If
+X is the immediate master of the mount, or if there's no dominant peer
+group under the same root, then only the "master:X" field is present
+and not the "propagate_from:X" field.
+
+For more information on mount propagation see:
+
+ Documentation/filesystems/sharedsubtree.txt
+
------------------------------------------------------------------------------
projects / linux-2.6 / blobdiff