For Thursday, June 11th 2009, I'm Jon Masters with a summary of today's LKML tra
ffic.

In today's issue: The floodgates have opened, early SLAB allocation, userspace
notification of filesystem error events, and fsnotify infrastructure.

The floodgates have opened. Merge window or not, the floodgates have well and
truly opened now, with large number of tree updates flying around, all
targeting what will someday become kernel 2.6.31. The record, as usual, goes
to the village of Ingo Molnar, who managed to send out 27 unique tree branch
pull requests yesterday. Most of these were x86 and scheduler related
(including removal of MEMORY_HOTPLUG_RESERVE code, and a new "glove box" BIOS
sandbox environment from Peter Anvin), but he did also find some time to push
IRQ updates (including more 32/64 merging), and a new version of the
performance counters patch series, for good measure. Ingo's locking branch
includes a new "atomic_dec_and_mutex_lock" API function call, though there
are probably others hiding in there amongst the huge number of patches.

Ingo's "urgent" x86 topic branch pull request came accompanying a remark that
Linus might "have a look whether in hindsight you'd have preferred to have any
of these upstream sooner, in the final week of .30. We generally only send you
lots-of-boxes-affected fixes after the final -rc". Linus was overwhelming
positive about the .30 experience, only really moaning that new CONFIG options
should never default to 'y' - which had been the case (he cited, amongst other
things, CONFIG_FTRACE) - and even eliciting a "Good job", which is high praise.

Other tree pull requests today included ext4 updates from Ted T'so (he noted
that most of these have been in testing since at least 30-rc8 if not a lot
before that point), IDE updates (part 1) from Bartlomiej Zolnierkiewicz,
KVM updates (Avi Kivity) - including MSI (Message Signalled Interrupts)
support, a rework of the interrupt code, improved smp performance, and
architecture code updates - Super-H updates (Paul Mundt), GFS2 updates (Steven
Whitehouse), a first round of block patches (Jens Axboe), jfs (Dave Kleikamp),
some libata quickies (Jezz Garzik), and Brtfs updates (Chris Mason). Chris
wanrs that the Btrfs update includes a forward rolling format change that
older kernels won't be able to read - conversion is automatic on mount. To
avoid locking testers into 2.6.31-rc, Chris is going to maintain a stable
branch of btrfs changes for 2.6.30, to give a stable kernel option too.

James Morris did get the memo about 2.6.30. In announcing what would be in the
security-testing tree for 2.6.31, he remarked that "Linus has asked people to
test 2.6.30 for a week before opening the merge window" - suggesting he will
be formally requesting a pull later. In his tree, there are a number of IMA,
SELinux, TOMOYO, and TPM fixes, as one might expect, including Christoph
Lameter's "use mmap_min_addr independently of security models" patches that
were under such heavy discussion upstream last week.

Early SLAB allocation (replacing bootmem). Pekka J Enberg has been busy today.
He posted a new tree implementing early SLAB availability, then updated it
several times (v2, v3), while also beginning to post what are likely to be many
small patch updates replacing use of bootmem with direct SLAB allocated
memory. For example, one patch substituted several calls to
alloc_bootmem_cpumask_var with calls to alloc_cpu_var. On a slight tangent,
Pekka debated with Christoph Lameter about disabling SLUB debugging if it
increases the minimum page order - instead logging that this was disabled, for
exmaple to the kernel global ring buffer. Christoph is concerned that this
leads to a situation in which some slabs have debug on and some do not, which
is, needless to say, a confusing circumstance to find oneself in.

Userspace notification of filesystem errors. Denis Karpov posted version 2 of
his patchset intended to add notification of certain filesystem errors, via
the use of sysfs and uevents. The use case cited was that of a hand-held
device containing large FAT volumes on MMC that are error prone. Rather than
performing a read-only remount on error, Denis wants userland to be able to
react to this and "do something about fixing the FS". The fact that he works
for Nokia, and that they make embedded Linux devices, suggests that this is a
common enough problem for their users. There are almost certainly many more.

fsnotify. On a similar filesystem notification note, Eric Paris posted a pull
request for Linus to take a new filesystem notification implementation called
fsnotify that reimplements inotify-user and dnotify on top of a generic
infrastructure. Eric says that he will work with Al (Viro) over the coming
days in order to find a way to merge the last in the kernel user of inotify
(audit) so that "we can [start] to kick that old inotify code out. Big winner
here, new extensible notification framework and we shrink struct inode".

The latest kernel release is: 2.6.30, which was released by Linus on Tuesday.
Although the merge window isn't officially open, large numbers of patches and
requests are flying around nonetheless.

Stephen Rothwell posted a linux-next tree for June 11th. Since Wednesday, the
Voyager tree has been removed (while it is being reorganized) - no doubt James
will be devastated, a number of (Ingo) sub-trees have been replaced with
"tip", and the tree continues to fail to build in an allyesconfig build
configuration for powerpc. There were a number of other conflicts and build
issues logged in todays posting. The total tree count (following the
re-organization of Ingo's tip bits) falls to 129.

That's a summary of today's LKML traffic. For further information visit kernel.o
rg. I'm Jon Masters.