X-Git-Url: https://git.decadent.org.uk/gitweb/?p=kernel-news-talk.git;a=blobdiff_plain;f=index.html;h=12c844c561d94da49c17153299ec0870902c0eb0;hp=0aae408aa2f139e354323a5ad2b5362ca0a84d30;hb=c8edb32ab191e7e9e3cab0174437a51c680de859;hpb=dff8a4f998aee65ebb951187c8b731f5a3d78491
diff --git a/index.html b/index.html
index 0aae408..12c844c 100644
--- a/index.html
+++ b/index.html
@@ -253,6 +253,106 @@
+
+
Btrfs offline dedupe [3.12]
+
+ -
+ Btrfs generally does COW rather than updating in-place, allowing
+ snapshots and file copies to defer the actual copying and save
+ space
+
+ -
+ Filesystems may still end up with multiple copies of the same
+ file content
+
+ -
+ Btrfs doesn't actively merge these duplicates, but userland can
+ tell it to do so
+
+ -
+ Many file dedupe tools are packaged for Debian, but not one that
+ works with this Btrfs feature, e.g. bedup
+
+
+
+
+
+
nftables [3.13]
+
+ -
+ Linux has several firewall APIs - iptables, ip6tables, arptables
+ and ebtables
+
+ -
+ All require a specific kernel module for each type of match
+ and each possible action
+
+ -
+ Userland could only use the four protocol-specific APIs,
+ although the internal netfilter API is more flexible
+
+ -
+ nftables exposes more of this flexibility, allowing userland
+ to provide firewall code for a specialised VM (similar to BPF)
+
+ -
+ nftables userland tool uses this API and is already packaged
+
+ -
+ Eventually, the old APIs will be removed and the old userland
+ tools must be ported to use nftables
+
+
+
+
+
+
User-space lockdep [3.14]
+
+ -
+ Kernel threads and interrupts all run in same address space,
+ using several different synchronisation mechanisms
+
+ -
+ Easy to introduce bugs that can result in deadlock, but hard to
+ reproduce them
+
+ -
+ Kernel's 'lockdep' system dynamically tracks locking operations
+ and detects potential deadlocks
+
+ -
+ Now available as a userland library! Except we need to package
+ it (build from linux-tools source package)
+
+
+
+
+
+
arm64 and ppc64el ports
+
+ -
+ 'arm64' architecture was added in Linux 3.7, but was not yet
+ usable, and no real hardware was available at the time
+
+ -
+ Upstream Linux arm64 kernel, and Debian packages, should now run
+ on emulators and real hardware
+
+ -
+ 'powerpc' architecture has been available for many years,
+ but didn't support kernel running little-endian
+
+ -
+ Linux 3.13 added little-endian kernel suport, along with new
+ userland ELF ABI variant - we call it ppc64el
+
+ -
+ Both ports now being bootstrapped in unstable and are candidates
+ for jessie release
+
+
+
+
Questions?