With the release of the
Linus let it be known
that he thought the final 3.4 release was probably not too far away. That
can only mean one thing: it's time to look at the statistics for this
development cycle. 3.4 was an active cycle, with an interesting surprise
As of this writing, Linus has merged just over 10,700 changes for 3.4; those changes
were contributed from 1,259 developers. The total growth of the kernel
source this time around is 215,000 lines. The developers most active in
this cycle were:
|Most active 3.4 developers|
|By changed lines|
|Mark A. Allyn||10976||1.6%|
Mark Brown finds himself at the top of the list of changeset contributors
for the second cycle in a row; as usual, he has done a great deal of work
with sound drivers and related subsystems. Russell King is the chief ARM
maintainer; he has also taken an active role in the refactoring and cleanup
of the ARM architecture code. Johannes Berg continues to do a lot of work
with the mac80211 layer and the iwlwifi driver, Al Viro has been improving
the VFS API and fixing issues throughout the kernel, and Axel Lin has done
a lot of cleanup work in the ALSA and regulator subsystems and beyond.
Joe Perches leads the "lines changed" column with coding-style fixes, pr_*() conversions, and related work.
Dan Magenheimer added the "ramster" memory sharing mechanism to the staging
Linux-next maintainer Stephen Rothwell made it into the "lines
changed" column with the removal of a lot of old PowerPC code. Greg
Kroah-Hartman works all over the tree, but the bulk of his changed lines
were to be found in the staging tree.
Some 195 companies contributed changes during the 3.4 development cycle.
The top contributors this time around were:
|Most active 3.4 employers|
|By lines changed|
A longstanding invariant in the above table has been Red Hat as the top
corporate contributor; in 3.4, however, Red Hat has been pushed down one
position by Intel. Red Hat's contributions are down somewhat; 960
changesets in 3.4 compared to 1,290 in 3.3. But the more significant
change is the burst of activity from Intel. This work is mostly
centered around support for Intel's own hardware, as one would expect, but
also extends to things like support for the x32 ABI.
Meanwhile, Texas Instruments continues the growth in participation seen
over the last few years, as do a number of other mobile and embedded
companies. Once upon a time, it was said that Linux development was
dominated by "big iron" enterprise-oriented companies; those companies have
not gone away, but they are clearly not the only driving force behind Linux
kernel development at this point.
On the other hand, the participation by volunteers is at the
lowest level seen in many cycles, continuing a longstanding trend.
A brief focus on ARM
Recent development cycles have seen a lot of work in the ARM subtree, and
3.4 is no exception; 1,100 changesets touched code in arch/arm
this time around. Those changes were contributed by 178 developers
representing 51 companies. Among those companies, the most active were:
|Most active 3.4 employers (ARM subtree)|
|By lines changed|
ARM is clearly an active area for consultants, who contributed over 13% of
the changes this time around. Otherwise, there are few surprises to be
seen in this area; the companies working in the mobile area are the biggest
contributors to the ARM tree, while those focused on other types of systems
have little presence here.
There is one other way to look at ARM development. Much of the work on ARM
is done through the Linaro consortium. Many developers contributing code
from a linaro.com address are "on loan" from other companies; the above
table, to the extent possible, credits those changes to the "real" employer
that paid for the work. If, instead, all changes from a Linaro address are
credited to Linaro, the results change: Linaro, with 11.9% of all the
changes in arch/arm, becomes the top employer, though it still
accounts for fewer changes than independent consultants do. Linaro clearly
has become an important part of the ARM development community.
In summary, it has been another busy and productive development cycle in
the kernel community. Despite the usual hiccups, things are stabilizing
and chances are good that 3.4-rc7 will be the last prepatch, meaning that
this cycle will be a relatively short one. There is little rest for kernel
developers, though; the 3.5 cycle with its frantic merge window will start
shortly thereafter. Stay tuned to LWN, as always, for ongoing coverage of
development in this large and energetic community.
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