From c9de560ded61faa5b754137b7753da252391c55a Mon Sep 17 00:00:00 2001 From: Alex Tomas Date: Tue, 29 Jan 2008 00:19:52 -0500 Subject: ext4: Add multi block allocator for ext4 Signed-off-by: Alex Tomas Signed-off-by: Andreas Dilger Signed-off-by: Aneesh Kumar K.V Signed-off-by: Eric Sandeen Signed-off-by: "Theodore Ts'o" --- Documentation/filesystems/proc.txt | 39 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) (limited to 'Documentation/filesystems/proc.txt') diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt index dec9945..4413a2d 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 -- cgit v1.1