Re: [PATCH v3] of: cache phandle nodes to reduce cost of of_find_node_by_phandle()

From: Chintan Pandya
Date: Wed Feb 28 2018 - 08:27:17 EST




On 2/15/2018 6:22 AM, frowand.list@xxxxxxxxx wrote:

+static void of_populate_phandle_cache(void)
+{
+ unsigned long flags;
+ u32 cache_entries;
+ struct device_node *np;
+ u32 phandles = 0;
+
+ raw_spin_lock_irqsave(&devtree_lock, flags);
+
+ kfree(phandle_cache);
+ phandle_cache = NULL;
+
+ for_each_of_allnodes(np)
+ if (np->phandle && np->phandle != OF_PHANDLE_ILLEGAL)
+ phandles++;
+
+ cache_entries = roundup_pow_of_two(phandles);
+ phandle_cache_mask = cache_entries - 1;
+
+ phandle_cache = kcalloc(cache_entries, sizeof(*phandle_cache),
+ GFP_ATOMIC);
+

NULL check of phandle_cache would be good to have.

+ for_each_of_allnodes(np)
+ if (np->phandle && np->phandle != OF_PHANDLE_ILLEGAL)
+ phandle_cache[np->phandle & phandle_cache_mask] = np;
+
+ raw_spin_unlock_irqrestore(&devtree_lock, flags);
+}


Chintan
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