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Diffstat (limited to 'Documentation/filesystems/proc.txt')
| -rw-r--r-- | Documentation/filesystems/proc.txt | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt index dec99455321f..4413a2d4646f 100644 --- a/Documentation/filesystems/proc.txt +++ b/Documentation/filesystems/proc.txt @@ -857,6 +857,45 @@ CPUs. 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 |