Messages in this thread | | | Date | Mon, 23 Jun 2014 22:28:02 -0400 | From | Steven Rostedt <> | Subject | Re: [PATCH 0/3] static keys: fix test/set races |
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Cleaning out my INBOX I found this patch series. It seems to have been forgotten about. It ended up with Ingo and Peter agreeing with the way things should be done and I thought Jason was going to send an update. But that seems to never have happened.
Does this patch series still look legit? Should we pursue it?
-- Steve
On Fri, 28 Jun 2013 22:30:28 +0000 (GMT) jbaron@akamai.com wrote:
> Hi, > > As pointed out by Andi Kleen, some static key users can be racy because they > check the value of the key->enabled, and then subsequently update the branch > direction. A number of call sites have 'higher' level locking that avoids this > race, but the usage in the scheduler features does not. See: > http://lkml.indiana.edu/hypermail/linux/kernel/1304.2/01655.html > > Thus, introduce a new API that does the check and set under the > 'jump_label_mutex'. This should also allow to simplify call sites a bit. > > Users of static keys should use either the inc/dec or the set_true/set_false > API. > > Thanks, > > -Jason > > > Jason Baron (3): > static_keys: Add a static_key_slow_set_true()/false() interface > sched: fix static keys race in sched_feat > udp: make use of static_key_slow_set_true() interface > > Documentation/static-keys.txt | 8 ++++++++ > include/linux/jump_label.h | 30 ++++++++++++++++++++++++++++++ > kernel/jump_label.c | 40 ++++++++++++++++++++++++++++++++++++++++ > kernel/sched/core.c | 12 +++++------- > kernel/sched/sched.h | 10 +++++----- > net/ipv4/udp.c | 9 ++++----- > net/ipv6/udp.c | 9 ++++----- > 7 files changed, 96 insertions(+), 22 deletions(-) >
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