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| author |   Paul E. McKenney <paulmck@kernel.org> | 2024-12-19 16:08:54 -0800 |
|---|---|---|
| committer |   Boqun Feng <boqun.feng@gmail.com> | 2025-02-05 07:12:05 -0800 |
| commit | 795e7efec6ea7e9d597c3fced9f5307fae467cb0 (patch) | |
| tree | 7a87ada5b2ac2bbc590a2a79382c215680932e5a /include | |
| parent | srcu: Pull ->srcu_{un,}lock_count into a new srcu_ctr structure (diff) | |
| download | wireguard-linux-795e7efec6ea7e9d597c3fced9f5307fae467cb0.tar.xz wireguard-linux-795e7efec6ea7e9d597c3fced9f5307fae467cb0.zip | |
srcu: Make SRCU readers use ->srcu_ctrs for counter selection
This commit causes SRCU readers to use ->srcu_ctrs for counter
selection instead of ->srcu_idx. This takes another step towards
array-indexing-free SRCU readers.
[ paulmck: Apply kernel test robot feedback. ]
Co-developed-by: Z qiang <qiang.zhang1211@gmail.com>
Signed-off-by: Z qiang <qiang.zhang1211@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Tested-by: kernel test robot <oliver.sang@intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: <bpf@vger.kernel.org>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/srcutree.h | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/include/linux/srcutree.h b/include/linux/srcutree.h index c794d599db5c..1b01ced61a45 100644 --- a/include/linux/srcutree.h +++ b/include/linux/srcutree.h @@ -101,6 +101,7 @@ struct srcu_usage { */ struct srcu_struct { unsigned int srcu_idx; /* Current rdr array element. */ + struct srcu_ctr __percpu *srcu_ctrp; struct srcu_data __percpu *sda; /* Per-CPU srcu_data array. */ struct lockdep_map dep_map; struct srcu_usage *srcu_sup; /* Update-side data. */ @@ -167,6 +168,7 @@ struct srcu_struct { #define __SRCU_STRUCT_INIT(name, usage_name, pcpu_name) \ { \ .sda = &pcpu_name, \ + .srcu_ctrp = &pcpu_name.srcu_ctrs[0], \ __SRCU_STRUCT_INIT_COMMON(name, usage_name) \ } @@ -222,13 +224,12 @@ void srcu_torture_stats_print(struct srcu_struct *ssp, char *tt, char *tf); */ static inline int __srcu_read_lock_lite(struct srcu_struct *ssp) { - int idx; + struct srcu_ctr __percpu *scp = READ_ONCE(ssp->srcu_ctrp); RCU_LOCKDEP_WARN(!rcu_is_watching(), "RCU must be watching srcu_read_lock_lite()."); - idx = READ_ONCE(ssp->srcu_idx) & 0x1; - this_cpu_inc(ssp->sda->srcu_ctrs[idx].srcu_locks.counter); /* Y */ + this_cpu_inc(scp->srcu_locks.counter); /* Y */ barrier(); /* Avoid leaking the critical section. */ - return idx; + return scp - &ssp->sda->srcu_ctrs[0]; } /* |