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| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2008-01-25 23:08:24 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-01-25 23:08:24 +0300 |
| commit | e260be673a15b6125068270e0216a3bfbfc12f87 (patch) | |
| tree | f50760606d395bf6faa9e865f814761a3c88d32c /include/linux/sched.h | |
| parent | e0ecfa7917cafe72f4a75f87e8bb5d8d51dc534f (diff) | |
| download | linux-e260be673a15b6125068270e0216a3bfbfc12f87.tar.xz | |
Preempt-RCU: implementation
This patch implements a new version of RCU which allows its read-side
critical sections to be preempted. It uses a set of counter pairs
to keep track of the read-side critical sections and flips them
when all tasks exit read-side critical section. The details
of this implementation can be found in this paper -
http://www.rdrop.com/users/paulmck/RCU/OLSrtRCU.2006.08.11a.pdf
and the article-
http://lwn.net/Articles/253651/
This patch was developed as a part of the -rt kernel development and
meant to provide better latencies when read-side critical sections of
RCU don't disable preemption. As a consequence of keeping track of RCU
readers, the readers have a slight overhead (optimizations in the paper).
This implementation co-exists with the "classic" RCU implementations
and can be switched to at compiler.
Also includes RCU tracing summarized in debugfs.
[ akpm@linux-foundation.org: build fixes on non-preempt architectures ]
Signed-off-by: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Dipankar Sarma <dipankar@in.ibm.com>
Signed-off-by: Paul E. McKenney <paulmck@us.ibm.com>
Reviewed-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include/linux/sched.h')
| -rw-r--r-- | include/linux/sched.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index f2044e707004..72e1b8ecfbe1 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -974,6 +974,11 @@ struct task_struct { int nr_cpus_allowed; unsigned int time_slice; +#ifdef CONFIG_PREEMPT_RCU + int rcu_read_lock_nesting; + int rcu_flipctr_idx; +#endif /* #ifdef CONFIG_PREEMPT_RCU */ + #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) struct sched_info sched_info; #endif |