rcu: Prevent needless ->gp_seq_needed update in __note_gp_changes()

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Currently, __note_gp_changes() checks to see if the rcu_node structure's
->gp_seq_needed is greater than or equal to that of the rcu_data
structure, and if so, updates the rcu_data structure's ->gp_seq_needed
field.  This results in a useless store in the case where the two fields
are equal.

This commit therefore carries out this store only in the case where the
rcu_node structure's ->gp_seq_needed is strictly greater than that of
the rcu_data structure.

Signed-off-by: "Zhang, Jun" <jun.zhang@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Link: https://lkml.kernel.org/r/88DC34334CA3444C85D647DBFA962C2735AD5F77@SHSMSX104.ccr.corp.intel.com

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Zhang, Jun 2018-12-19 10:37:34 -08:00 • committed by Paul E. McKenney

parent 1d1f898df6

commit 13dc7d0c7a

1 changed files with 1 additions and 1 deletions

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kernel/rcu/tree.c

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