6.17-stable review patch. If anyone has any objections, please let me know.
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From: Zqiang qiang.zhang@linux.dev
[ Upstream commit e6a43aeb71852a39432332dcc3a6d11bb464b075 ]
Currently, the srcu_gp_start_if_needed() is always be invoked in preempt disable's critical section, this commit therefore remove redundant preempt_disable/enable() in srcu_gp_start_if_needed() and adds a call to lockdep_assert_preemption_disabled() in order to enable lockdep to diagnose mistaken invocations of this function from preempts-enabled code.
Fixes: 65b4a59557f6 ("srcu: Make Tiny SRCU explicitly disable preemption") Signed-off-by: Zqiang qiang.zhang@linux.dev Signed-off-by: Paul E. McKenney paulmck@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/rcu/srcutiny.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/kernel/rcu/srcutiny.c b/kernel/rcu/srcutiny.c index 6e9fe2ce1075d..e3b64a5e0ec7e 100644 --- a/kernel/rcu/srcutiny.c +++ b/kernel/rcu/srcutiny.c @@ -176,10 +176,9 @@ static void srcu_gp_start_if_needed(struct srcu_struct *ssp) { unsigned long cookie;
- preempt_disable(); // Needed for PREEMPT_LAZY + lockdep_assert_preemption_disabled(); // Needed for PREEMPT_LAZY cookie = get_state_synchronize_srcu(ssp); if (ULONG_CMP_GE(READ_ONCE(ssp->srcu_idx_max), cookie)) { - preempt_enable(); return; } WRITE_ONCE(ssp->srcu_idx_max, cookie); @@ -189,7 +188,6 @@ static void srcu_gp_start_if_needed(struct srcu_struct *ssp) else if (list_empty(&ssp->srcu_work.entry)) list_add(&ssp->srcu_work.entry, &srcu_boot_list); } - preempt_enable(); }
/*