Re: [PATCH v5 06/13] lockdep: Implement crossrelease feature

From	Peter Zijlstra <peterz@infradead.org>
Newsgroups	linux.kernel
Subject	Re: [PATCH v5 06/13] lockdep: Implement crossrelease feature
Date	2017-02-28 14:20 +0100
Message-ID	<tfPR9-4Up-35@gated-at.bofh.it> (permalink)
References	<t0YjD-4z4-5@gated-at.bofh.it> <t0Ytl-4D1-41@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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> +#ifdef CONFIG_LOCKDEP_CROSSRELEASE
> +
> +#define idx(t)			((t)->xhlock_idx)
> +#define idx_prev(i)		((i) ? (i) - 1 : MAX_XHLOCKS_NR - 1)
> +#define idx_next(i)		(((i) + 1) % MAX_XHLOCKS_NR)

Note that:

#define idx_prev(i)		(((i) - 1) % MAX_XHLOCKS_NR)
#define idx_next(i)		(((i) + 1) % MAX_XHLOCKS_NR)

is more symmetric and easier to understand.

> +
> +/* For easy access to xhlock */
> +#define xhlock(t, i)		((t)->xhlocks + (i))
> +#define xhlock_prev(t, l)	xhlock(t, idx_prev((l) - (t)->xhlocks))
> +#define xhlock_curr(t)		xhlock(t, idx(t))

So these result in an xhlock pointer

> +#define xhlock_incr(t)		({idx(t) = idx_next(idx(t));})

This does not; which is confusing seeing how they share the same
namespace; also incr is weird.

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Re: [PATCH v5 06/13] lockdep: Implement crossrelease feature Peter Zijlstra <peterz@infradead.org> - 2017-02-28 14:20 +0100
  Re: [PATCH v5 06/13] lockdep: Implement crossrelease feature Byungchul Park <byungchul.park@lge.com> - 2017-02-28 15:20 +0100
    Re: [PATCH v5 06/13] lockdep: Implement crossrelease feature Peter Zijlstra <peterz@infradead.org> - 2017-02-28 19:40 +0100
      Re: [PATCH v5 06/13] lockdep: Implement crossrelease feature Byungchul Park <byungchul.park@lge.com> - 2017-03-01 06:30 +0100

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