Messages in this thread | | | Date | Mon, 13 Jan 2020 16:51:28 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH v2 4/6] locking/lockdep: Reuse freed chain_hlocks entries |
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On Mon, Dec 16, 2019 at 10:15:15AM -0500, Waiman Long wrote: > +#define CHAIN_HLOCKS_MASK 0xffff
> +static inline void set_chain_block(int offset, int size, int next) > +{ > + if (unlikely(offset < 0)) { > + chain_block_buckets[0] = next; > + return; > + } > + chain_hlocks[offset] = (next >> 16) | CHAIN_BLK_FLAG; > + chain_hlocks[offset + 1] = next & CHAIN_HLOCKS_MASK; > + if (size > MAX_CHAIN_BUCKETS) { > + chain_hlocks[offset + 2] = size >> 16; > + chain_hlocks[offset + 3] = size & CHAIN_HLOCKS_MASK; > + } > +}
AFAICT HLOCKS_MASK is superfluous. That is, you're assigning to a u16, it will truncate automagically.
But if you want to make it more explicit, something like:
chain_hlocks[offset + 1] = (u16)next;
might be easier to read still.
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