Provide a place in sysfs (/sys/class/bdi) for the backing_dev_info object. This allows us to see and set the various BDI specific variables. In particular this properly exposes the read-ahead window for all relevant users and /sys/block/<block>/queue/read_ahead_kb should be deprecated. With patient help from Kay Sievers and Greg KH [mszeredi@suse.cz] - split off NFS and FUSE changes into separate patches - document new sysfs attributes under Documentation/ABI - do bdi_class_init as a core_initcall, otherwise the "default" BDI won't be initialized - remove bdi_init_fmt macro, it's not used very much [akpm@linux-foundation.org: fix ia64 warning] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Kay Sievers <kay.sievers@vrfy.org> Acked-by: Greg KH <greg@kroah.com> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
47 lines
1.0 KiB
Plaintext
47 lines
1.0 KiB
Plaintext
What: /sys/class/bdi/<bdi>/
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Date: January 2008
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Contact: Peter Zijlstra <a.p.zijlstra@chello.nl>
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Description:
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Provide a place in sysfs for the backing_dev_info object.
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This allows us to see and set the various BDI specific variables.
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The <bdi> identifier can be either of the following:
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MAJOR:MINOR
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Device number for block devices, or value of st_dev on
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non-block filesystems which provide their own BDI, such as NFS
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and FUSE.
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default
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The default backing dev, used for non-block device backed
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filesystems which do not provide their own BDI.
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Files under /sys/class/bdi/<bdi>/
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---------------------------------
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read_ahead_kb (read-write)
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Size of the read-ahead window in kilobytes
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reclaimable_kb (read-only)
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Reclaimable (dirty or unstable) memory destined for writeback
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to this device
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writeback_kb (read-only)
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Memory currently under writeback to this device
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dirty_kb (read-only)
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Global threshold for reclaimable + writeback memory
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bdi_dirty_kb (read-only)
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Current threshold on this BDI for reclaimable + writeback
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memory
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