From: Peter Zijlstra <peterz@infradead.org>
To: Waiman Long <longman@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>, Will Deacon <will.deacon@arm.com>,
linux-kernel@vger.kernel.org,
Bart Van Assche <bvanassche@acm.org>
Subject: Re: [PATCH v2 4/6] locking/lockdep: Reuse freed chain_hlocks entries
Date: Mon, 13 Jan 2020 16:51:28 +0100 [thread overview]
Message-ID: <20200113155128.GX2844@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20191216151517.7060-5-longman@redhat.com>
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.
next prev parent reply other threads:[~2020-01-13 15:51 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-16 15:15 [PATCH v2 0/6] locking/lockdep: Reuse zapped chain_hlocks entries Waiman Long
2019-12-16 15:15 ` [PATCH v2 1/6] locking/lockdep: Track number of zapped classes Waiman Long
2020-01-13 14:55 ` Peter Zijlstra
2020-01-13 14:58 ` Waiman Long
2020-01-13 16:02 ` Bart Van Assche
2019-12-16 15:15 ` [PATCH v2 2/6] locking/lockdep: Throw away all lock chains with zapped class Waiman Long
2020-01-13 15:18 ` Peter Zijlstra
2020-01-13 15:44 ` Waiman Long
2020-01-13 16:05 ` Bart Van Assche
2020-01-13 16:15 ` Waiman Long
2019-12-16 15:15 ` [PATCH v2 3/6] locking/lockdep: Track number of zapped lock chains Waiman Long
2019-12-16 15:15 ` [PATCH v2 4/6] locking/lockdep: Reuse freed chain_hlocks entries Waiman Long
2020-01-13 15:51 ` Peter Zijlstra [this message]
2020-01-13 16:04 ` Waiman Long
2020-01-13 15:58 ` Peter Zijlstra
2020-01-13 16:24 ` Waiman Long
2020-01-14 9:46 ` Peter Zijlstra
2020-01-14 19:16 ` Waiman Long
2020-01-15 10:44 ` Peter Zijlstra
2020-01-15 19:26 ` Waiman Long
2020-01-13 15:59 ` Peter Zijlstra
2020-01-13 16:03 ` Waiman Long
2019-12-16 15:15 ` [PATCH v2 5/6] locking/lockdep: Decrement irq context counters when removing lock chain Waiman Long
2020-01-14 9:53 ` Peter Zijlstra
2020-01-14 15:04 ` Waiman Long
2019-12-16 15:15 ` [PATCH v2 6/6] locking/lockdep: Display irq_context names in /proc/lockdep_chains Waiman Long
2020-01-06 15:54 ` [PATCH v2 0/6] locking/lockdep: Reuse zapped chain_hlocks entries Waiman Long
2020-01-06 16:50 ` Peter Zijlstra
2020-01-06 16:52 ` Waiman Long
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