From: Paul E. McKenney Date: Fri, 25 Jul 2014 18:21:47 +0000 (-0700) Subject: rcu: Fix attempt to avoid unsolicited offloading of callbacks X-Git-Tag: fixes-against-v3.18-rc2~103^2~1^2~16^3~13 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f4579fc57cf4244057b713b1f73f4dc9f0b11e97;p=pandora-kernel.git rcu: Fix attempt to avoid unsolicited offloading of callbacks Commit b58cc46c5f6b (rcu: Don't offload callbacks unless specifically requested) failed to adjust the callback lists of the CPUs that are known to be no-CBs CPUs only because they are also nohz_full= CPUs. This failure can result in callbacks that are posted during early boot getting stranded on nxtlist for CPUs whose no-CBs property becomes apparent late, and there can also be spurious warnings about offline CPUs posting callbacks. This commit fixes these problems by adding an early-boot rcu_init_nohz() that properly initializes the no-CBs CPUs. Note that kernels built with CONFIG_RCU_NOCB_CPU_ALL=y or with CONFIG_RCU_NOCB_CPU=n do not exhibit this bug. Neither do kernels booted without the nohz_full= boot parameter. Signed-off-by: Paul E. McKenney Reviewed-by: Pranith Kumar Tested-by: Paul Gortmaker --- Reading git-diff-tree failed