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| author | Paul E. McKenney <paulmck@linux.ibm.com> | 2019-04-16 08:19:43 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.ibm.com> | 2019-08-13 14:35:49 -0700 |
| commit | 750d7f6a434ff4640fa825dfb1eccb44e79fb6af (patch) | |
| tree | 8bb80a109d8cc342fe1a1e2d59b54e1a670e7a3f /kernel/rcu | |
| parent | ce5215c1342c6c89b3c3c45fea82cddf0b013787 (diff) | |
| download | linux-750d7f6a434ff4640fa825dfb1eccb44e79fb6af.tar.bz2 | |
rcu/nocb: Add checks for offloaded callback processing
This commit is a preparatory patch for offloaded callbacks using the
same ->cblist structure used by non-offloaded callbacks. It therefore
adds rcu_segcblist_is_offloaded() calls where they will be needed when
!rcu_segcblist_is_enabled() no longer flags the offloaded case. It also
adds checks in rcu_do_batch() to ensure that there are no missed checks:
Currently, it should not be possible for offloaded execution to reach
rcu_do_batch(), though this will change later in this series.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Diffstat (limited to 'kernel/rcu')
| -rw-r--r-- | kernel/rcu/tree.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 6f5c96c4f9a3..969ba292a669 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -210,7 +210,8 @@ static long rcu_get_n_cbs_cpu(int cpu) { struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu); - if (rcu_segcblist_is_enabled(&rdp->cblist)) /* Online normal CPU? */ + if (rcu_segcblist_is_enabled(&rdp->cblist) && + !rcu_segcblist_is_offloaded(&rdp->cblist)) /* Online normal CPU? */ return rcu_segcblist_n_cbs(&rdp->cblist); return rcu_get_n_cbs_nocb_cpu(rdp); /* Works for offline, too. */ } @@ -2081,6 +2082,7 @@ static void rcu_do_batch(struct rcu_data *rdp) struct rcu_cblist rcl = RCU_CBLIST_INITIALIZER(rcl); long bl, count; + WARN_ON_ONCE(rdp->cblist.offloaded); /* If no callbacks are ready, just return. */ if (!rcu_segcblist_ready_cbs(&rdp->cblist)) { trace_rcu_batch_start(rcu_state.name, @@ -2299,7 +2301,8 @@ static __latent_entropy void rcu_core(void) /* No grace period and unregistered callbacks? */ if (!rcu_gp_in_progress() && - rcu_segcblist_is_enabled(&rdp->cblist)) { + rcu_segcblist_is_enabled(&rdp->cblist) && + !rcu_segcblist_is_offloaded(&rdp->cblist)) { local_irq_save(flags); if (!rcu_segcblist_restempty(&rdp->cblist, RCU_NEXT_READY_TAIL)) rcu_accelerate_cbs_unlocked(rnp, rdp); @@ -2514,7 +2517,8 @@ __call_rcu(struct rcu_head *head, rcu_callback_t func, int cpu, bool lazy) rdp = this_cpu_ptr(&rcu_data); /* Add the callback to our list. */ - if (unlikely(!rcu_segcblist_is_enabled(&rdp->cblist)) || cpu != -1) { + if (unlikely(!rcu_segcblist_is_enabled(&rdp->cblist)) || + rcu_segcblist_is_offloaded(&rdp->cblist) || cpu != -1) { int offline; if (cpu != -1) @@ -2750,6 +2754,7 @@ static int rcu_pending(void) /* Has RCU gone idle with this CPU needing another grace period? */ if (!rcu_gp_in_progress() && rcu_segcblist_is_enabled(&rdp->cblist) && + !rcu_segcblist_is_offloaded(&rdp->cblist) && !rcu_segcblist_restempty(&rdp->cblist, RCU_NEXT_READY_TAIL)) return 1; |