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authorBjorn Helgaas <bhelgaas@google.com>2012-09-13 16:41:01 +0200
committerBjorn Helgaas <bhelgaas@google.com>2012-09-13 16:41:01 +0200
commit78890b5989d96ddce989cde929c45ceeded0fcaf (patch)
tree4e2da81fc7c97f11aee174b1eedac110c9a68b3a /Documentation/block/queue-sysfs.txt
parentMerge branch 'pci/stephen-const' into next (diff)
parentLinux 3.6-rc5 (diff)
downloadlinux-78890b5989d96ddce989cde929c45ceeded0fcaf.tar.xz
linux-78890b5989d96ddce989cde929c45ceeded0fcaf.zip
Merge commit 'v3.6-rc5' into next
* commit 'v3.6-rc5': (1098 commits) Linux 3.6-rc5 HID: tpkbd: work even if the new Lenovo Keyboard driver is not configured Remove user-triggerable BUG from mpol_to_str xen/pciback: Fix proper FLR steps. uml: fix compile error in deliver_alarm() dj: memory scribble in logi_dj Fix order of arguments to compat_put_time[spec|val] xen: Use correct masking in xen_swiotlb_alloc_coherent. xen: fix logical error in tlb flushing xen/p2m: Fix one-off error in checking the P2M tree directory. powerpc: Don't use __put_user() in patch_instruction powerpc: Make sure IPI handlers see data written by IPI senders powerpc: Restore correct DSCR in context switch powerpc: Fix DSCR inheritance in copy_thread() powerpc: Keep thread.dscr and thread.dscr_inherit in sync powerpc: Update DSCR on all CPUs when writing sysfs dscr_default powerpc/powernv: Always go into nap mode when CPU is offline powerpc: Give hypervisor decrementer interrupts their own handler powerpc/vphn: Fix arch_update_cpu_topology() return value ARM: gemini: fix the gemini build ... Conflicts: drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c drivers/rapidio/devices/tsi721.c
Diffstat (limited to 'Documentation/block/queue-sysfs.txt')
-rw-r--r--Documentation/block/queue-sysfs.txt64
1 files changed, 64 insertions, 0 deletions
diff --git a/Documentation/block/queue-sysfs.txt b/Documentation/block/queue-sysfs.txt
index 6518a55273e7..e54ac1d53403 100644
--- a/Documentation/block/queue-sysfs.txt
+++ b/Documentation/block/queue-sysfs.txt
@@ -9,20 +9,71 @@ These files are the ones found in the /sys/block/xxx/queue/ directory.
Files denoted with a RO postfix are readonly and the RW postfix means
read-write.
+add_random (RW)
+----------------
+This file allows to trun off the disk entropy contribution. Default
+value of this file is '1'(on).
+
+discard_granularity (RO)
+-----------------------
+This shows the size of internal allocation of the device in bytes, if
+reported by the device. A value of '0' means device does not support
+the discard functionality.
+
+discard_max_bytes (RO)
+----------------------
+Devices that support discard functionality may have internal limits on
+the number of bytes that can be trimmed or unmapped in a single operation.
+The discard_max_bytes parameter is set by the device driver to the maximum
+number of bytes that can be discarded in a single operation. Discard
+requests issued to the device must not exceed this limit. A discard_max_bytes
+value of 0 means that the device does not support discard functionality.
+
+discard_zeroes_data (RO)
+------------------------
+When read, this file will show if the discarded block are zeroed by the
+device or not. If its value is '1' the blocks are zeroed otherwise not.
+
hw_sector_size (RO)
-------------------
This is the hardware sector size of the device, in bytes.
+iostats (RW)
+-------------
+This file is used to control (on/off) the iostats accounting of the
+disk.
+
+logical_block_size (RO)
+-----------------------
+This is the logcal block size of the device, in bytes.
+
max_hw_sectors_kb (RO)
----------------------
This is the maximum number of kilobytes supported in a single data transfer.
+max_integrity_segments (RO)
+---------------------------
+When read, this file shows the max limit of integrity segments as
+set by block layer which a hardware controller can handle.
+
max_sectors_kb (RW)
-------------------
This is the maximum number of kilobytes that the block layer will allow
for a filesystem request. Must be smaller than or equal to the maximum
size allowed by the hardware.
+max_segments (RO)
+-----------------
+Maximum number of segments of the device.
+
+max_segment_size (RO)
+---------------------
+Maximum segment size of the device.
+
+minimum_io_size (RO)
+--------------------
+This is the smallest preferred io size reported by the device.
+
nomerges (RW)
-------------
This enables the user to disable the lookup logic involved with IO
@@ -45,11 +96,24 @@ per-block-cgroup request pool. IOW, if there are N block cgroups,
each request queue may have upto N request pools, each independently
regulated by nr_requests.
+optimal_io_size (RO)
+--------------------
+This is the optimal io size reported by the device.
+
+physical_block_size (RO)
+------------------------
+This is the physical block size of device, in bytes.
+
read_ahead_kb (RW)
------------------
Maximum number of kilobytes to read-ahead for filesystems on this block
device.
+rotational (RW)
+---------------
+This file is used to stat if the device is of rotational type or
+non-rotational type.
+
rq_affinity (RW)
----------------
If this option is '1', the block layer will migrate request completions to the