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-<title>What's new in the Linux kernel - DebConf 2013</title>
+<title>What's new in the Linux kernel - DebConf 2014</title>
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-<h1>DebConf 2013</h1>
+<h1>DebConf 2014</h1>
<h2>What's new in the Linux kernel</h2>
</div>
<div class="slide">
<h1>What's new in the Linux kernel</h1>
<object data="tux-debian.svg" width="35%" align="right"></object>
+<h2>and what's missing in Debian</h2>
<h3>Ben Hutchings</h3>
</div>
<ul>
<li>
Professional software engineer by day, Debian developer by night
+ (or sometimes the other way round)
</li>
<li>
Regular Linux contributor in both roles since 2008
</li>
<li>
- Maintaining a net driver in my day job, plus core networking
- and PCI code as necessary
+ Working on various drivers and kernel code in my day job
</li>
<li>
Debian kernel team member, now doing most of the unstable
<li>
Linux is released about 5 times a year (plus stable updates
every week or two)
+ <ul>
+ <li>
+ ...though some features aren't ready to use when they firat
+ appear in a release
+ </li>
+ </ul>
</li>
<li>
- For 'wheezy' we chose to freeze with Linux 3.2, which was
- getting pretty old by the time of release
+ Since my talk last year, Linus has made 6 releases (3.11-3.16)
</li>
<li>
Good news: we have lots of new kernel features in testing/unstable
</div>
<div class="slide">
- <h1>Team device driver [3.3]</h1>
- <ul class="incremental">
- <li>
- Alternative to the bonding driver - simpler, modular, high-level
- control deferred to userland
- </li>
- <li>
- Basic configuration can be done with <tt>ip</tt>, but it really
- needs new tools - <tt>teamd</tt>, <tt>teamnl</tt>, etc.
- </li>
- <li>
- Make it work: see
- <a href="http://bugs.debian.org/695850">http://bugs.debian.org/695850</a>
- </li>
- </ul>
-</div>
-
-<div class="slide">
- <h1>Transcendent memory [3.0-3.5]</h1>
- <ul class="incremental">
- <li>
- Abstract storage for memory pages, expected to be slower than
- regular memory but faster than disk
- </li>
- <li>
- Can provide a second layer of page cache (cleancache and frontswap)
- </li>
- <li>
- Pages stored by hypervisor (Xen), compressed local memory
- (zcache) or cluster of machines (RAMster)
- </li>
- <li>
- Not yet enabled in Debian kernels, and needs some thought about
- configuration
- </li>
- <li>
- Make it work: see
- <a href="https://lwn.net/Articles/454795/">https://lwn.net/Articles/454795/</a>
- and send proposal to debian-kernel
- </li>
- </ul>
-</div>
-
-<div class="slide">
- <h1>New KMS drivers [3.3-3.10]</h1>
+ <h1>Recap of last year's features (1)</h1>
<ul class="incremental">
<li>
- DRM/KMS drivers added for old, new and virtual hardware -
- AST, DisplayLink, Hyper-V, Matrox G200, QEMU Cirrus
- </li>
- <li>
- Should be more robust than purely user-mode drivers, and
- compatible with Secure Boot
+ Team device driver: userland package (libteam) was uploaded in
+ October
</li>
<li>
- Current X drivers don't work with these, so the kernel drivers
- are disabled for now
- </li>
- <li>
- Make it work: join the X Strike Force and package the new X
- drivers
- </li>
- </ul>
-</div>
-
-<div class="slide">
- <h1>Module signing [3.7]</h1>
- <ul class="incremental">
- <li>
- Kernel modules can be signed at build time, and the kernel
- configured to refuse loading unsigned modules
+ Transcendent memory: frontswap, zswap and Xen tmem will be
+ enabled in next kernel upload
</li>
<li>
- Necessary but not sufficient to implement Secure Boot -
- we would also need signed kernel images and some other
- restrictions when booted in this mode
+ New KMS drivers: should all work with current Xorg drivers
</li>
<li>
- Make Secure Boot work: come to the meeting on Tuesday
+ Module signing: still not enabled, but probably will be if we
+ do Secure Boot
</li>
</ul>
</div>
<div class="slide">
- <h1>More support for discard</h1>
+ <h1>Recap of last year's features (2)</h1>
<ul class="incremental">
<li>
- Flash devices (and thin-provisioned SANs) can be more efficient
- if the filesystem 'discards' unused disk space
+ More support for discard: still not enabled at install time
+ (<a href="https://bugs.debian.org/690977">#690977</a>)
</li>
<li>
- Requires support in hardware, driver, filesystem and any layered
- device drivers - e.g. LVM, RAID (added in 3.7)
+ More support for containers: XFS was fixed, and user namespaces
+ have been enabled
</li>
<li>
- Must be explicitly enabled, but d-i doesn't do this by default
+ bcache: userland package (bcache-tools) still not quite ready
+ (<a href="https://bugs.debian.org/708132">#708132</a>)
</li>
<li>
- Make it work: fix <a href="http://bugs.debian.org/690977">http://bugs.debian.org/690977</a>
+ ARMv7 multiplatform: d-i works on <em>some</em> platforms but
+ I'm still not sure which. Some progress on GPU drivers, but not
+ in Debian yet.
</li>
</ul>
</div>
<div class="slide">
- <h1>User namespaces [3.7]</h1>
- <ul class="incremental">
- <li>
- One of the last missing pieces for OpenVZ-like containers
- </li>
- <li>
- Each user namespace has its own <tt>root</tt> user with
- privileges over the users and processes in that namespace - but
- not the whole system
- </li>
- <li>
- Currently somewhat experimental, and requires filesystem
- changes which haven't been done for XFS
- </li>
+ <h1>Unnamed temporary files [3.11]</h1>
+ <ul>
<li>
- Make it work: send patches to upstream XFS developers (this
- one's hard)
+ Open directory with option <tt>O_TMPFILE</tt> to create an
+ unnamed temporary file on that filesystem
</li>
- </ul>
-</div>
-
-<div class="slide">
- <h1>bcache [3.10]</h1>
- <ul class="incremental">
<li>
- Turns a fast block device into a cache for a larger, slower
- device (see also: dm-cache, EnhanceIO)
+ As with <tt>tmpfile()</tt>, the file disppears on
+ last <tt>close()</tt>
</li>
<li>
- Needs its own set of userland tools
+ File can be linked into the filesystem using
+ <tt>linkat(..., AT_EMPTY_PATH)</tt>, allowing for 'atomic'
+ creation of file with complete contents and metadata
</li>
<li>
- Make it work:
- see <a href="http://bugs.debian.org/708132">http://bugs.debian.org/708132</a>
- (maybe just needs a sponsor)
+ Not supported on all filesystem types, so you will usually need
+ a fallback
</li>
</ul>
</div>
projects / kernel-news-talk.git / blobdiff