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Diffstat (limited to 'Documentation/block/queue-sysfs.txt')
| -rw-r--r-- | Documentation/block/queue-sysfs.txt | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/Documentation/block/queue-sysfs.txt b/Documentation/block/queue-sysfs.txt index 3a29f8914df9..e5d914845be6 100644 --- a/Documentation/block/queue-sysfs.txt +++ b/Documentation/block/queue-sysfs.txt @@ -20,7 +20,7 @@ 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) +discard_max_hw_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. @@ -29,6 +29,14 @@ 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_max_bytes (RW) +---------------------- +While discard_max_hw_bytes is the hardware limit for the device, this +setting is the software limit. Some devices exhibit large latencies when +large discards are issued, setting this value lower will make Linux issue +smaller discards and potentially help reduce latencies induced by large +discard operations. + discard_zeroes_data (RO) ------------------------ When read, this file will show if the discarded block are zeroed by the |