X-Git-Url: https://git.decadent.org.uk/gitweb/?a=blobdiff_plain;ds=inline;f=index.html;h=31c5d34d1e27a5330b890a9513c964c6e4932350;hb=f2996f28a502a51711217c9c6fab3458c79bf886;hp=9e99a51a015bd62246401b74a3fc0340fd41ac61;hpb=61fa05974dac42b20d57f734218f5725dc66abdc;p=kernel-news-talk.git
diff --git a/index.html b/index.html
index 9e99a51..31c5d34 100644
--- a/index.html
+++ b/index.html
@@ -155,7 +155,7 @@
unnamed temporary file on that filesystem
- As with tmpfile(), the file disppears on
+ As with tmpfile(), the file disappears on
last close()
@@ -257,9 +257,12 @@
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
+ Btrfs generally copies and frees blocks, rather than updating
+ in-place
+
+ -
+ This allows snapshots and file copies to copy-by-reference,
+ deferring the real copying until changes are made
-
Filesystems may still end up with multiple copies of the same
@@ -284,12 +287,11 @@
and ebtables
-
- All require a specific kernel module for each type of match
- and each possible action
+ All limited to single protocol, and need a kernel module for
+ each match type and each action
-
- Userland could only use the four protocol-specific APIs,
- although the internal netfilter API is more flexible
+ Kernel's internal netfilter API is more flexible
-
nftables exposes more of this flexibility, allowing userland
@@ -299,7 +301,7 @@
nftables userland tool uses this API and is already packaged
-
- Eventually, the old APIs will be removed and the old userland
+ Eventually, old APIs will be removed and old userland
tools must be ported to use nftables
@@ -343,7 +345,7 @@
but didn't support kernel running little-endian
- Linux 3.13 added little-endian kernel suport, along with new
+ Linux 3.13 added little-endian kernel support, along with new
userland ELF ABI variant - we call it ppc64el
@@ -380,6 +382,32 @@
+
+
Multiqueue block devices [3.16]
+
+ -
+ Each block device has a command queue (possibly shared with
+ other devices)
+
+ -
+ Queue may be partly implemented by hardware (NCQ) or only
+ in software
+
+ -
+ A single queue means initiation is serialised and completion
+ involves IPI - can be bottleneck for fast devices
+
+ -
+ High-end SSDs support multiple queues, but kernel needed changes
+ to use them
+
+ -
+ mtip32xx driver now supports multiqueue, but SCSI
+ drivers don't yet - may be backport-able?
+
+
+
+
Questions?