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11da3403e9
For nearly all commands in U-Boot the '?' variable is handled the same way with 0 meaning success, 1 meaning any failure. Explain this in the general rules section of the cmdline documentation (with a link to a counter example) and then remove the redundant wording from most commands. We retain a section about the return value in a number of places where we are doing something such as always returning a specific value or we have useful additional information to go along with the normal return codes. Signed-off-by: Tom Rini <trini@konsulko.com> Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
72 lines
1.4 KiB
ReStructuredText
72 lines
1.4 KiB
ReStructuredText
.. SPDX-License-Identifier: GPL-2.0+
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.. Copyright 2023, Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
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.. index::
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single: blkcache (command)
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blkcache command
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================
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Synopsis
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--------
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::
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blkcache show
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blkcache configure <blocks> <entries>
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Description
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-----------
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The *blkcache* command is used to control the size of the block cache and to
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display statistics.
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The block cache buffers data read from block devices. This speeds up the access
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to file-systems.
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show
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show and reset statistics
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configure
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set the maximum number of cache entries and the maximum number of blocks per
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entry
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blocks
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maximum number of blocks per cache entry. The block size is device specific.
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The initial value is 8.
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entries
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maximum number of entries in the cche. The initial value is 32.
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Example
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-------
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.. code-block::
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=> blkcache show
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hits: 296
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misses: 149
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entries: 7
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max blocks/entry: 8
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max cache entries: 32
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=> blkcache show
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hits: 0
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misses: 0
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entries: 7
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max blocks/entry: 8
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max cache entries: 32
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=> blkcache configure 16 64
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changed to max of 64 entries of 16 blocks each
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=> blkcache show
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hits: 0
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misses: 0
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entries: 0
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max blocks/entry: 16
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max cache entries: 64
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=>
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Configuration
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-------------
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The blkcache command is only available if CONFIG_CMD_BLOCK_CACHE=y.
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