diff options
| author | Paul E. McKenney <paulmck@kernel.org> | 2023-03-17 13:28:04 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2023-04-04 08:35:28 -0700 |
| commit | f4d01a259374ef358cd6b00a96b4dfc0fb05a844 (patch) | |
| tree | 9f74a46df60daae70eecbf2f5bc56119d6c54d31 /kernel/rcu/srcutree.c | |
| parent | 3e67cb8a3c6251c86e5d058d8ee4e1909bc25af0 (diff) | |
srcu: Use static init for statically allocated in-module srcu_struct
Further shrinking the srcu_struct structure is eased by requiring
that in-module srcu_struct structures rely more heavily on static
initialization. In particular, this preserves the property that
a module-load-time srcu_struct initialization can fail only due
to memory-allocation failure of the per-CPU srcu_data structures.
It might also slightly improve robustness by keeping the number of memory
allocations that must succeed down percpu_alloc() call.
This is in preparation for splitting an srcu_usage structure out
of the srcu_struct structure.
[ paulmck: Fold in qiang1.zhang@intel.com feedback. ]
Cc: Christoph Hellwig <hch@lst.de>
Tested-by: Sachin Sant <sachinp@linux.ibm.com>
Tested-by: "Zhang, Qiang1" <qiang1.zhang@intel.com>
Tested-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'kernel/rcu/srcutree.c')
| -rw-r--r-- | kernel/rcu/srcutree.c | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c index ab4ee58af84b..7e6e7dfb1a87 100644 --- a/kernel/rcu/srcutree.c +++ b/kernel/rcu/srcutree.c @@ -1873,13 +1873,14 @@ void __init srcu_init(void) static int srcu_module_coming(struct module *mod) { int i; + struct srcu_struct *ssp; struct srcu_struct **sspp = mod->srcu_struct_ptrs; - int ret; for (i = 0; i < mod->num_srcu_structs; i++) { - ret = init_srcu_struct(*(sspp++)); - if (WARN_ON_ONCE(ret)) - return ret; + ssp = *(sspp++); + ssp->sda = alloc_percpu(struct srcu_data); + if (WARN_ON_ONCE(!ssp->sda)) + return -ENOMEM; } return 0; } @@ -1888,10 +1889,16 @@ static int srcu_module_coming(struct module *mod) static void srcu_module_going(struct module *mod) { int i; + struct srcu_struct *ssp; struct srcu_struct **sspp = mod->srcu_struct_ptrs; - for (i = 0; i < mod->num_srcu_structs; i++) - cleanup_srcu_struct(*(sspp++)); + for (i = 0; i < mod->num_srcu_structs; i++) { + ssp = *(sspp++); + if (!rcu_seq_state(smp_load_acquire(&ssp->srcu_gp_seq_needed)) && + !WARN_ON_ONCE(!ssp->sda_is_static)) + cleanup_srcu_struct(ssp); + free_percpu(ssp->sda); + } } /* Handle one module, either coming or going. */ |