path: root/Documentation/device-mapper/dm-crypt.txt
diff options
authorAlex Shi <alex.shi@linaro.org>2015-06-25 16:17:21 +0800
committerAlex Shi <alex.shi@linaro.org>2015-06-25 16:19:06 +0800
commitbd4e9a26373331ef6f185500c72a8836eb7c82d9 (patch)
tree13384e7649be7bb88ab9524efcbc602be85d5020 /Documentation/device-mapper/dm-crypt.txt
parent2528dbd348dd541e090594b7aac3f62351078388 (diff)
parent2cb9802eeb7f919f97df05b16ec128f4f5af366d (diff)
Merge branch 'linux-linaro-lsk-v3.14' into linux-linaro-lsk-v3.14-androidlsk-v3.14-15.07-android
Conflicts: fs/exec.c Solutions: follow commit d221244a7 sched: move no_new_privs into new atomic flags to use task_no_new_privs(current).
Diffstat (limited to 'Documentation/device-mapper/dm-crypt.txt')
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:
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
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.
+ 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.
+ 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