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| author | Alex Shi <alex.shi@linaro.org> | 2015-06-24 11:49:40 +0800 |
|---|---|---|
| committer | Alex Shi <alex.shi@linaro.org> | 2015-06-24 11:49:40 +0800 |
| commit | 2cb9802eeb7f919f97df05b16ec128f4f5af366d (patch) | |
| tree | d4fc4d910049cccce116b563c7eea3eb9c2c017a /Documentation/device-mapper/dm-crypt.txt | |
| parent | 1787a2cb15ec9ae90c095b99f90366d4d3af9f21 (diff) | |
| parent | efacff3850bf899cfe9c70b1a01c7c9f5eb01df0 (diff) | |
Merge branch 'v3.14/topic/dm-crypt' into linux-linaro-lsk-v3.14
To fix dm-crypt performance bug.
Diffstat (limited to 'Documentation/device-mapper/dm-crypt.txt')
| -rw-r--r-- | Documentation/device-mapper/dm-crypt.txt | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/Documentation/device-mapper/dm-crypt.txt b/Documentation/device-mapper/dm-crypt.txt index c81839b52c4d..692171fe9da0 100644 --- a/Documentation/device-mapper/dm-crypt.txt +++ b/Documentation/device-mapper/dm-crypt.txt @@ -5,7 +5,7 @@ Device-Mapper's "crypt" target provides transparent encryption of block devices using the kernel crypto API. For a more detailed description of supported parameters see: -http://code.google.com/p/cryptsetup/wiki/DMCrypt +https://gitlab.com/cryptsetup/cryptsetup/wikis/DMCrypt Parameters: <cipher> <key> <iv_offset> <device path> \ <offset> [<#opt_params> <opt_params>] @@ -51,7 +51,7 @@ Parameters: <cipher> <key> <iv_offset> <device path> \ Otherwise #opt_params is the number of following arguments. Example of optional parameters section: - 1 allow_discards + 3 allow_discards same_cpu_crypt submit_from_crypt_cpus allow_discards Block discard requests (a.k.a. TRIM) are passed through the crypt device. @@ -63,11 +63,24 @@ allow_discards used space etc.) if the discarded blocks can be located easily on the device later. +same_cpu_crypt + Perform encryption using the same cpu that IO was submitted on. + The default is to use an unbound workqueue so that encryption work + is automatically balanced between available CPUs. + +submit_from_crypt_cpus + Disable offloading writes to a separate thread after encryption. + There are some situations where offloading write bios from the + encryption threads to a single thread degrades performance + significantly. The default is to offload write bios to the same + thread because it benefits CFQ to have writes submitted using the + same context. + Example scripts =============== LUKS (Linux Unified Key Setup) is now the preferred way to set up disk encryption with dm-crypt using the 'cryptsetup' utility, see -http://code.google.com/p/cryptsetup/ +https://gitlab.com/cryptsetup/cryptsetup [[ #!/bin/sh |