From: Uladzislau Rezki (Sony) Date: Tue, 11 Apr 2023 13:13:41 +0000 (+0200) Subject: rcu/kvfree: Do not run a page work if a cache is disabled X-Git-Tag: v6.5-rc1~209^2^3~2 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=021a5ff8474379cd6c23e9b0e97aa27e5ff66a8b;p=thirdparty%2Fkernel%2Flinux.git rcu/kvfree: Do not run a page work if a cache is disabled By default the cache size is 5 pages per CPU, but it can be disabled at boot time by setting the rcu_min_cached_objs to zero. When that happens, the current code will uselessly set an hrtimer to schedule refilling this cache with zero pages. This commit therefore streamlines this process by simply refusing the set the hrtimer when rcu_min_cached_objs is zero. Signed-off-by: Uladzislau Rezki (Sony) Signed-off-by: Paul E. McKenney --- diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 51d84eabf6453..18f592bf6dc61 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -3225,6 +3225,10 @@ static void fill_page_cache_func(struct work_struct *work) static void run_page_cache_worker(struct kfree_rcu_cpu *krcp) { + // If cache disabled, bail out. + if (!rcu_min_cached_objs) + return; + if (rcu_scheduler_active == RCU_SCHEDULER_RUNNING && !atomic_xchg(&krcp->work_in_progress, 1)) { if (atomic_read(&krcp->backoff_page_cache_fill)) {