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| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2009-09-23 09:50:41 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-09-23 19:46:29 +0200 |
| commit | fc2219d49ef1606e7fd2c88af2b423b01ff3d319 (patch) | |
| tree | 1c1cba7e4334898a98cf0e2c992e8cfef4b34979 /kernel/rcutree.h | |
| parent | 0729e196147692d84d4c099fcff056eba2ed61d8 (diff) | |
| download | op-kernel-dev-fc2219d49ef1606e7fd2c88af2b423b01ff3d319.zip op-kernel-dev-fc2219d49ef1606e7fd2c88af2b423b01ff3d319.tar.gz | |
rcu: Clean up code based on review feedback from Josh Triplett
These issues identified during an old-fashioned face-to-face code
review extended over many hours.
o Bury various forms of the "rsp->completed == rsp->gpnum"
comparison into an rcu_gp_in_progress() function, which has
the beneficial side-effect of forcing consistent use of
ACCESS_ONCE().
o Replace hand-coded arithmetic with DIV_ROUND_UP().
o Bury several "!list_empty(&rnp->blocked_tasks[rnp->gpnum & 0x01])"
instances into an rcu_preempted_readers() function, as this
expression indicates that there are no readers blocked
within RCU read-side critical sections blocking the current
grace period. (Though there might well be similar readers
blocking the next grace period.)
o Remove a dangling rcu_restart_cpu() declaration that has
been dangling for almost 20 minor releases of the kernel.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: akpm@linux-foundation.org
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <12537246442687-git-send-email->
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/rcutree.h')
| -rw-r--r-- | kernel/rcutree.h | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/kernel/rcutree.h b/kernel/rcutree.h index 8e8287a..9aa8c8a 100644 --- a/kernel/rcutree.h +++ b/kernel/rcutree.h @@ -48,14 +48,14 @@ #elif NR_CPUS <= RCU_FANOUT_SQ # define NUM_RCU_LVLS 2 # define NUM_RCU_LVL_0 1 -# define NUM_RCU_LVL_1 (((NR_CPUS) + RCU_FANOUT - 1) / RCU_FANOUT) +# define NUM_RCU_LVL_1 DIV_ROUND_UP(NR_CPUS, RCU_FANOUT) # define NUM_RCU_LVL_2 (NR_CPUS) # define NUM_RCU_LVL_3 0 #elif NR_CPUS <= RCU_FANOUT_CUBE # define NUM_RCU_LVLS 3 # define NUM_RCU_LVL_0 1 -# define NUM_RCU_LVL_1 (((NR_CPUS) + RCU_FANOUT_SQ - 1) / RCU_FANOUT_SQ) -# define NUM_RCU_LVL_2 (((NR_CPUS) + (RCU_FANOUT) - 1) / (RCU_FANOUT)) +# define NUM_RCU_LVL_1 DIV_ROUND_UP(NR_CPUS, RCU_FANOUT_SQ) +# define NUM_RCU_LVL_2 DIV_ROUND_UP(NR_CPUS, RCU_FANOUT) # define NUM_RCU_LVL_3 NR_CPUS #else # error "CONFIG_RCU_FANOUT insufficient for NR_CPUS" |
