• Joel Fernandes (Google)'s avatar
    rcu: Disable laziness if lazy-tracking says so · cf7066b9
    Joel Fernandes (Google) authored
    During suspend, we see failures to suspend 1 in 300-500 suspends.
    Looking closer, it appears that asynchronous RCU callbacks are being
    queued as lazy even though synchronous callbacks are expedited. These
    delays appear to not be very welcome by the suspend/resume code as
    evidenced by these occasional suspend failures.
    
    This commit modifies call_rcu() to check if rcu_async_should_hurry(),
    which will return true if we are in suspend or in-kernel boot.
    
    [ paulmck: Alphabetize local variables. ]
    
    Ignoring the lazy hint makes the 3000 suspend/resume cycles pass
    reliably on a 12th gen 12-core Intel CPU, and there is some evidence
    that it also slightly speeds up boot performance.
    
    Fixes: 3cb278e7 ("rcu: Make call_rcu() lazy to save power")
    Signed-off-by: default avatarJoel Fernandes (Google) <joel@joelfernandes.org>
    Signed-off-by: default avatarPaul E. McKenney <paulmck@kernel.org>
    cf7066b9
tree.c 159 KB