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| author | Takashi Iwai <tiwai@suse.de> | 2009-02-23 08:17:28 +0100 | 
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2009-02-23 08:17:28 +0100 | 
| commit | 66a101dda6b26ee566aa9cadcbea904a41d2b268 (patch) | |
| tree | e03b5d40b7b88bb0a2f432bceba4680086d6d3a1 /Documentation/filesystems | |
| parent | b1a0aac05f044e78a589bfd7a9e2334aa640eb45 (diff) | |
| parent | 28b7e343ee63454d563a71d2d5f769fc297fd5ad (diff) | |
Merge branch 'topic/hwdep-cleanup' into topic/hdsp
Diffstat (limited to 'Documentation/filesystems')
| -rw-r--r-- | Documentation/filesystems/nfs-rdma.txt | 4 | ||||
| -rw-r--r-- | Documentation/filesystems/proc.txt | 288 | 
2 files changed, 4 insertions, 288 deletions
| diff --git a/Documentation/filesystems/nfs-rdma.txt b/Documentation/filesystems/nfs-rdma.txt index 44bd766f2e5..85eaeaddd27 100644 --- a/Documentation/filesystems/nfs-rdma.txt +++ b/Documentation/filesystems/nfs-rdma.txt @@ -251,7 +251,7 @@ NFS/RDMA Setup      Instruct the server to listen on the RDMA transport: -    $ echo rdma 2050 > /proc/fs/nfsd/portlist +    $ echo rdma 20049 > /proc/fs/nfsd/portlist    - On the client system @@ -263,7 +263,7 @@ NFS/RDMA Setup      Regardless of how the client was built (module or built-in), use this      command to mount the NFS/RDMA server: -    $ mount -o rdma,port=2050 <IPoIB-server-name-or-address>:/<export> /mnt +    $ mount -o rdma,port=20049 <IPoIB-server-name-or-address>:/<export> /mnt      To verify that the mount is using RDMA, run "cat /proc/mounts" and check      the "proto" field for the given mount. diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt index d105eb45282..bbebc3a43ac 100644 --- a/Documentation/filesystems/proc.txt +++ b/Documentation/filesystems/proc.txt @@ -1371,292 +1371,8 @@ auto_msgmni default value is 1.  2.4 /proc/sys/vm - The virtual memory subsystem  ----------------------------------------------- -The files  in  this directory can be used to tune the operation of the virtual -memory (VM)  subsystem  of  the  Linux  kernel. - -vfs_cache_pressure ------------------- - -Controls the tendency of the kernel to reclaim the memory which is used for -caching of directory and inode objects. - -At the default value of vfs_cache_pressure=100 the kernel will attempt to -reclaim dentries and inodes at a "fair" rate with respect to pagecache and -swapcache reclaim.  Decreasing vfs_cache_pressure causes the kernel to prefer -to retain dentry and inode caches.  Increasing vfs_cache_pressure beyond 100 -causes the kernel to prefer to reclaim dentries and inodes. - -dirty_background_bytes ----------------------- - -Contains the amount of dirty memory at which the pdflush background writeback -daemon will start writeback. - -If dirty_background_bytes is written, dirty_background_ratio becomes a function -of its value (dirty_background_bytes / the amount of dirtyable system memory). - -dirty_background_ratio ----------------------- - -Contains, as a percentage of the dirtyable system memory (free pages + mapped -pages + file cache, not including locked pages and HugePages), the number of -pages at which the pdflush background writeback daemon will start writing out -dirty data. - -If dirty_background_ratio is written, dirty_background_bytes becomes a function -of its value (dirty_background_ratio * the amount of dirtyable system memory). - -dirty_bytes ------------ - -Contains the amount of dirty memory at which a process generating disk writes -will itself start writeback. - -If dirty_bytes is written, dirty_ratio becomes a function of its value -(dirty_bytes / the amount of dirtyable system memory). - -dirty_ratio ------------ - -Contains, as a percentage of the dirtyable system memory (free pages + mapped -pages + file cache, not including locked pages and HugePages), the number of -pages at which a process which is generating disk writes will itself start -writing out dirty data. - -If dirty_ratio is written, dirty_bytes becomes a function of its value -(dirty_ratio * the amount of dirtyable system memory). - -dirty_writeback_centisecs -------------------------- - -The pdflush writeback daemons will periodically wake up and write `old' data -out to disk.  This tunable expresses the interval between those wakeups, in -100'ths of a second. - -Setting this to zero disables periodic writeback altogether. - -dirty_expire_centisecs ----------------------- - -This tunable is used to define when dirty data is old enough to be eligible -for writeout by the pdflush daemons.  It is expressed in 100'ths of a second.  -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. - -lowmem_reserve_ratio ---------------------- - -For some specialised workloads on highmem machines it is dangerous for -the kernel to allow process memory to be allocated from the "lowmem" -zone.  This is because that memory could then be pinned via the mlock() -system call, or by unavailability of swapspace. - -And on large highmem machines this lack of reclaimable lowmem memory -can be fatal. - -So the Linux page allocator has a mechanism which prevents allocations -which _could_ use highmem from using too much lowmem.  This means that -a certain amount of lowmem is defended from the possibility of being -captured into pinned user memory. - -(The same argument applies to the old 16 megabyte ISA DMA region.  This -mechanism will also defend that region from allocations which could use -highmem or lowmem). - -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 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 expression. - -(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 ------------- - -page-cluster controls the number of pages which are written to swap in -a single attempt.  The swap I/O size. - -It is a logarithmic value - setting it to zero means "1 page", setting -it to 1 means "2 pages", setting it to 2 means "4 pages", etc. - -The default value is three (eight pages at a time).  There may be some -small benefits in tuning this to a different value if your workload is -swap-intensive. - -overcommit_memory ------------------ - -Controls overcommit of system memory, possibly allowing processes -to allocate (but not use) more memory than is actually available. - - -0	-	Heuristic overcommit handling. Obvious overcommits of -		address space are refused. Used for a typical system. It -		ensures a seriously wild allocation fails while allowing -		overcommit to reduce swap usage.  root is allowed to -		allocate slightly more memory in this mode. This is the -		default. - -1	-	Always overcommit. Appropriate for some scientific -		applications. - -2	-	Don't overcommit. The total address space commit -		for the system is not permitted to exceed swap plus a -		configurable percentage (default is 50) of physical RAM. -		Depending on the percentage you use, in most situations -		this means a process will not be killed while attempting -		to use already-allocated memory but will receive errors -		on memory allocation as	appropriate. - -overcommit_ratio ----------------- - -Percentage of physical memory size to include in overcommit calculations -(see above.) - -Memory allocation limit = swapspace + physmem * (overcommit_ratio / 100) - -	swapspace = total size of all swap areas -	physmem = size of physical memory in system - -nr_hugepages and hugetlb_shm_group ----------------------------------- - -nr_hugepages configures number of hugetlb page reserved for the system. - -hugetlb_shm_group contains group id that is allowed to create SysV shared -memory segment using hugetlb page. - -hugepages_treat_as_movable --------------------------- - -This parameter is only useful when kernelcore= is specified at boot time to -create ZONE_MOVABLE for pages that may be reclaimed or migrated. Huge pages -are not movable so are not normally allocated from ZONE_MOVABLE. A non-zero -value written to hugepages_treat_as_movable allows huge pages to be allocated -from ZONE_MOVABLE. - -Once enabled, the ZONE_MOVABLE is treated as an area of memory the huge -pages pool can easily grow or shrink within. Assuming that applications are -not running that mlock() a lot of memory, it is likely the huge pages pool -can grow to the size of ZONE_MOVABLE by repeatedly entering the desired value -into nr_hugepages and triggering page reclaim. - -laptop_mode ------------ - -laptop_mode is a knob that controls "laptop mode". All the things that are -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/laptops/laptop-mode.txt. - -swap_token_timeout ------------------- - -This file contains valid hold time of swap out protection token. The Linux -VM has token based thrashing control mechanism and uses the token to prevent -unnecessary page faults in thrashing situation. The unit of the value is -second. The value would be useful to tune thrashing behavior. - -drop_caches ------------ - -Writing to this will cause the kernel to drop clean caches, dentries and -inodes from memory, causing that memory to become free. - -To free pagecache: -	echo 1 > /proc/sys/vm/drop_caches -To free dentries and inodes: -	echo 2 > /proc/sys/vm/drop_caches -To free pagecache, dentries and inodes: -	echo 3 > /proc/sys/vm/drop_caches - -As this is a non-destructive operation and dirty objects are not freeable, the -user should run `sync' first. +Please see: Documentation/sysctls/vm.txt for a description of these +entries.  2.5 /proc/sys/dev - Device specific parameters | 
