<feed xmlns='http://www.w3.org/2005/Atom'>
<title>litmus-rt.git/Documentation/device-mapper, branch master</title>
<subtitle>The LITMUS^RT kernel.</subtitle>
<link rel='alternate' type='text/html' href='http://rtsrv.cs.unc.edu/cgit/cgit.cgi/litmus-rt.git/'/>
<entry>
<title>dm crypt: update URLs to new cryptsetup project page</title>
<updated>2015-04-15T16:10:24+00:00</updated>
<author>
<name>Milan Broz</name>
<email>gmazyland@gmail.com</email>
</author>
<published>2015-04-05T16:03:10+00:00</published>
<link rel='alternate' type='text/html' href='http://rtsrv.cs.unc.edu/cgit/cgit.cgi/litmus-rt.git/commit/?id=e44f23b32dc7916b2bc12817e2f723fefa21ba41'/>
<id>e44f23b32dc7916b2bc12817e2f723fefa21ba41</id>
<content type='text'>
Cryptsetup home page moved to GitLab.
Also remove link to abandonded Truecrypt page.

Signed-off-by: Milan Broz &lt;gmazyland@gmail.com&gt;
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Cryptsetup home page moved to GitLab.
Also remove link to abandonded Truecrypt page.

Signed-off-by: Milan Broz &lt;gmazyland@gmail.com&gt;
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>dm: add log writes target</title>
<updated>2015-04-15T16:10:24+00:00</updated>
<author>
<name>Josef Bacik</name>
<email>jbacik@fb.com</email>
</author>
<published>2015-03-20T14:50:37+00:00</published>
<link rel='alternate' type='text/html' href='http://rtsrv.cs.unc.edu/cgit/cgit.cgi/litmus-rt.git/commit/?id=0e9cebe724597a76ab1b0ebc0a21e16f7db11b47'/>
<id>0e9cebe724597a76ab1b0ebc0a21e16f7db11b47</id>
<content type='text'>
Introduce a new target that is meant for file system developers to test file
system integrity at particular points in the life of a file system.  We capture
all write requests and associated data and log them to a separate device
for later replay.  There is a userspace utility to do this replay.  The
idea behind this is to give file system developers a tool to verify that
the file system is always consistent.

Signed-off-by: Josef Bacik &lt;jbacik@fb.com&gt;
Reviewed-by: Zach Brown &lt;zab@zabbo.net&gt;
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Introduce a new target that is meant for file system developers to test file
system integrity at particular points in the life of a file system.  We capture
all write requests and associated data and log them to a separate device
for later replay.  There is a userspace utility to do this replay.  The
idea behind this is to give file system developers a tool to verify that
the file system is always consistent.

Signed-off-by: Josef Bacik &lt;jbacik@fb.com&gt;
Reviewed-by: Zach Brown &lt;zab@zabbo.net&gt;
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>dm verity: add error handling modes for corrupted blocks</title>
<updated>2015-04-15T16:10:22+00:00</updated>
<author>
<name>Sami Tolvanen</name>
<email>samitolvanen@google.com</email>
</author>
<published>2015-03-18T15:52:14+00:00</published>
<link rel='alternate' type='text/html' href='http://rtsrv.cs.unc.edu/cgit/cgit.cgi/litmus-rt.git/commit/?id=65ff5b7ddf0541f2b6e5cc59c47bfbf6cbcd91b8'/>
<id>65ff5b7ddf0541f2b6e5cc59c47bfbf6cbcd91b8</id>
<content type='text'>
Add device specific modes to dm-verity to specify how corrupted
blocks should be handled.  The following modes are defined:

  - DM_VERITY_MODE_EIO is the default behavior, where reading a
    corrupted block results in -EIO.

  - DM_VERITY_MODE_LOGGING only logs corrupted blocks, but does
    not block the read.

  - DM_VERITY_MODE_RESTART calls kernel_restart when a corrupted
    block is discovered.

In addition, each mode sends a uevent to notify userspace of
corruption and to allow further recovery actions.

The driver defaults to previous behavior (DM_VERITY_MODE_EIO)
and other modes can be enabled with an additional parameter to
the verity table.

Signed-off-by: Sami Tolvanen &lt;samitolvanen@google.com&gt;
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add device specific modes to dm-verity to specify how corrupted
blocks should be handled.  The following modes are defined:

  - DM_VERITY_MODE_EIO is the default behavior, where reading a
    corrupted block results in -EIO.

  - DM_VERITY_MODE_LOGGING only logs corrupted blocks, but does
    not block the read.

  - DM_VERITY_MODE_RESTART calls kernel_restart when a corrupted
    block is discovered.

In addition, each mode sends a uevent to notify userspace of
corruption and to allow further recovery actions.

The driver defaults to previous behavior (DM_VERITY_MODE_EIO)
and other modes can be enabled with an additional parameter to
the verity table.

Signed-off-by: Sami Tolvanen &lt;samitolvanen@google.com&gt;
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>dm thin: remove stale 'trim' message documentation</title>
<updated>2015-04-15T16:10:22+00:00</updated>
<author>
<name>Mike Snitzer</name>
<email>snitzer@redhat.com</email>
</author>
<published>2015-03-19T00:57:29+00:00</published>
<link rel='alternate' type='text/html' href='http://rtsrv.cs.unc.edu/cgit/cgit.cgi/litmus-rt.git/commit/?id=0e0e32c16cfd2eeaf4fd4f16aa6cccd1333ce1e0'/>
<id>0e0e32c16cfd2eeaf4fd4f16aa6cccd1333ce1e0</id>
<content type='text'>
The 'trim' message wasn't ever implemented.

Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The 'trim' message wasn't ever implemented.

Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>dm switch: fix Documentation to use plain text</title>
<updated>2015-03-31T16:03:49+00:00</updated>
<author>
<name>Mike Snitzer</name>
<email>snitzer@redhat.com</email>
</author>
<published>2015-02-27T20:25:31+00:00</published>
<link rel='alternate' type='text/html' href='http://rtsrv.cs.unc.edu/cgit/cgit.cgi/litmus-rt.git/commit/?id=e73f6e8a0de8ce28edef986d86720ef83dd2864f'/>
<id>e73f6e8a0de8ce28edef986d86720ef83dd2864f</id>
<content type='text'>
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>dm crypt: add 'submit_from_crypt_cpus' option</title>
<updated>2015-02-16T16:11:15+00:00</updated>
<author>
<name>Mikulas Patocka</name>
<email>mpatocka@redhat.com</email>
</author>
<published>2015-02-13T13:27:08+00:00</published>
<link rel='alternate' type='text/html' href='http://rtsrv.cs.unc.edu/cgit/cgit.cgi/litmus-rt.git/commit/?id=0f5d8e6ee758f7023e4353cca75d785b2d4f6abe'/>
<id>0f5d8e6ee758f7023e4353cca75d785b2d4f6abe</id>
<content type='text'>
Make it possible to disable offloading writes by setting the optional
'submit_from_crypt_cpus' table argument.

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 IO context.

Signed-off-by: Mikulas Patocka &lt;mpatocka@redhat.com&gt;
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Make it possible to disable offloading writes by setting the optional
'submit_from_crypt_cpus' table argument.

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 IO context.

Signed-off-by: Mikulas Patocka &lt;mpatocka@redhat.com&gt;
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>dm crypt: use unbound workqueue for request processing</title>
<updated>2015-02-16T16:10:59+00:00</updated>
<author>
<name>Mikulas Patocka</name>
<email>mpatocka@redhat.com</email>
</author>
<published>2015-02-13T13:23:09+00:00</published>
<link rel='alternate' type='text/html' href='http://rtsrv.cs.unc.edu/cgit/cgit.cgi/litmus-rt.git/commit/?id=f3396c58fd8442850e759843457d78b6ec3a9589'/>
<id>f3396c58fd8442850e759843457d78b6ec3a9589</id>
<content type='text'>
Use unbound workqueue by default so that work is automatically balanced
between available CPUs.  The original behavior of encrypting using the
same cpu that IO was submitted on can still be enabled by setting the
optional 'same_cpu_crypt' table argument.

Signed-off-by: Mikulas Patocka &lt;mpatocka@redhat.com&gt;
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Use unbound workqueue by default so that work is automatically balanced
between available CPUs.  The original behavior of encrypting using the
same cpu that IO was submitted on can still be enabled by setting the
optional 'same_cpu_crypt' table argument.

Signed-off-by: Mikulas Patocka &lt;mpatocka@redhat.com&gt;
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>dm cache policy mq: simplify ability to promote sequential IO to the cache</title>
<updated>2014-11-10T20:25:30+00:00</updated>
<author>
<name>Mike Snitzer</name>
<email>snitzer@redhat.com</email>
</author>
<published>2014-10-30T14:02:01+00:00</published>
<link rel='alternate' type='text/html' href='http://rtsrv.cs.unc.edu/cgit/cgit.cgi/litmus-rt.git/commit/?id=f1afb36a6102b52949c2c6d8eb250eddcce3fc5f'/>
<id>f1afb36a6102b52949c2c6d8eb250eddcce3fc5f</id>
<content type='text'>
Before, if the user wanted sequential IO to be promoted to the cache
they'd have to set sequential_threshold to some nebulous large value.

Now, the user may easily disable sequential IO detection (and sequential
IO's implicit bypass of the cache) by setting sequential_threshold to 0.

Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Before, if the user wanted sequential IO to be promoted to the cache
they'd have to set sequential_threshold to some nebulous large value.

Now, the user may easily disable sequential IO detection (and sequential
IO's implicit bypass of the cache) by setting sequential_threshold to 0.

Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>dm cache policy mq: tweak algorithm that decides when to promote a block</title>
<updated>2014-11-10T20:25:29+00:00</updated>
<author>
<name>Joe Thornber</name>
<email>ejt@redhat.com</email>
</author>
<published>2014-10-22T13:30:58+00:00</published>
<link rel='alternate' type='text/html' href='http://rtsrv.cs.unc.edu/cgit/cgit.cgi/litmus-rt.git/commit/?id=b155aa0e5a81ea1f05ff7aced0ec8e34c980c19e'/>
<id>b155aa0e5a81ea1f05ff7aced0ec8e34c980c19e</id>
<content type='text'>
Rather than maintaining a separate promote_threshold variable that we
periodically update we now use the hit count of the oldest clean
block.  Also add a fudge factor to discourage demoting dirty blocks.

With some tests this has a sizeable difference, because the old code
was too eager to demote blocks.  For example, device-mapper-test-suite's
git_extract_cache_quick test goes from taking 190 seconds, to 142
(linear on spindle takes 250).

Signed-off-by: Joe Thornber &lt;ejt@redhat.com&gt;
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Rather than maintaining a separate promote_threshold variable that we
periodically update we now use the hit count of the oldest clean
block.  Also add a fudge factor to discourage demoting dirty blocks.

With some tests this has a sizeable difference, because the old code
was too eager to demote blocks.  For example, device-mapper-test-suite's
git_extract_cache_quick test goes from taking 190 seconds, to 142
(linear on spindle takes 250).

Signed-off-by: Joe Thornber &lt;ejt@redhat.com&gt;
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>dm switch: efficiently support repetitive patterns</title>
<updated>2014-08-01T16:30:37+00:00</updated>
<author>
<name>Mikulas Patocka</name>
<email>mpatocka@redhat.com</email>
</author>
<published>2014-07-28T22:11:25+00:00</published>
<link rel='alternate' type='text/html' href='http://rtsrv.cs.unc.edu/cgit/cgit.cgi/litmus-rt.git/commit/?id=56b1ebf2d9798257c5932c8a0dd9da16796dbf36'/>
<id>56b1ebf2d9798257c5932c8a0dd9da16796dbf36</id>
<content type='text'>
Add support for quickly loading a repetitive pattern into the
dm-switch target.

In the "set_regions_mappings" message, the user may now use "Rn,m" as
one of the arguments.  "n" and "m" are hexadecimal numbers.  The "Rn,m"
argument repeats the last "n" arguments in the following "m" slots.

For example:
dmsetup message switch 0 set_region_mappings 1000:1 :2 R2,10
is equivalent to
dmsetup message switch 0 set_region_mappings 1000:1 :2 :1 :2 :1 :2 :1 :2 \
:1 :2 :1 :2 :1 :2 :1 :2 :1 :2

Requested-by: Jay Wang &lt;jwang@nimblestorage.com&gt;
Tested-by: Jay Wang &lt;jwang@nimblestorage.com&gt;
Signed-off-by: Mikulas Patocka &lt;mpatocka@redhat.com&gt;
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add support for quickly loading a repetitive pattern into the
dm-switch target.

In the "set_regions_mappings" message, the user may now use "Rn,m" as
one of the arguments.  "n" and "m" are hexadecimal numbers.  The "Rn,m"
argument repeats the last "n" arguments in the following "m" slots.

For example:
dmsetup message switch 0 set_region_mappings 1000:1 :2 R2,10
is equivalent to
dmsetup message switch 0 set_region_mappings 1000:1 :2 :1 :2 :1 :2 :1 :2 \
:1 :2 :1 :2 :1 :2 :1 :2 :1 :2

Requested-by: Jay Wang &lt;jwang@nimblestorage.com&gt;
Tested-by: Jay Wang &lt;jwang@nimblestorage.com&gt;
Signed-off-by: Mikulas Patocka &lt;mpatocka@redhat.com&gt;
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
