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From: Peter Zijlstra <peterz@infradead.org>
To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: linux-kernel@vger.kernel.org, Ingo Molnar <mingo@kernel.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	Will Deacon <will@kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	"Paul E . McKenney" <paulmck@kernel.org>,
	Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [PATCH 1/8] locking: Introduce local_lock()
Date: Fri, 22 May 2020 15:01:45 +0200	[thread overview]
Message-ID: <20200522130145.GN325280@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20200522110556.czizy72ak2nr32ve@linutronix.de>

On Fri, May 22, 2020 at 01:05:56PM +0200, Sebastian Andrzej Siewior wrote:
> On 2020-05-20 14:04:50 [+0200], Peter Zijlstra wrote:
> > On Tue, May 19, 2020 at 10:19:05PM +0200, Sebastian Andrzej Siewior wrote:
> > > +/**
> > > + * DEFINE_LOCAL_LOCK - Define and initialize a per CPU local lock
> > > + * @lock:	Name of the lock instance
> > > + */
> > > +#define DEFINE_LOCAL_LOCK(lvar)					\
> > > +	DEFINE_PER_CPU(struct local_lock, lvar) = { INIT_LOCAL_LOCK(lvar) }
> > > +
> > > +/**
> > > + * DECLARE_LOCAL_LOCK - Declare a defined per CPU local lock
> > > + * @lock:	Name of the lock instance
> > > + */
> > > +#define DECLARE_LOCAL_LOCK(lvar)				\
> > > +	DECLARE_PER_CPU(struct local_lock, lvar)
> > 
> > So I think I'm going to argue having these is a mistake. The local_lock
> > should be put in a percpu structure along with the data it actually
> > protects.
> 
> So I got rid of these and made the local_lock part of the per-CPU
> struct.

Great!

> > > +#ifdef CONFIG_DEBUG_LOCK_ALLOC
> > > +# define LL_DEP_MAP_INIT(lockname)	.dep_map = { .name = #lockname }
> > 
> > That wants to be:
> > 
> > 	.dep_map = {
> > 		.name = #lockname,
> > 		.wait_type_inner = LD_WAIT_SPIN,
> 
> Why LD_WAIT_SPIN and not LD_WAIT_SLEEP? On RT the lock becomes sleeping
> and none of the SPIN restrictions apply. 

Ah, then it wants to be LD_WAIT_CONFIG. I completely forgot what RT did
here.

  reply	other threads:[~2020-05-22 13:02 UTC|newest]

Thread overview: 48+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-19 20:19 [PATCH 0/8] Introduce local_lock() Sebastian Andrzej Siewior
2020-05-19 20:19 ` [PATCH 1/8] locking: " Sebastian Andrzej Siewior
2020-05-20 12:04   ` Peter Zijlstra
2020-05-22 11:05     ` Sebastian Andrzej Siewior
2020-05-22 13:01       ` Peter Zijlstra [this message]
2020-05-19 20:19 ` [PATCH 2/8] radix-tree: Use local_lock for protection Sebastian Andrzej Siewior
2020-05-19 20:45   ` Matthew Wilcox
2020-05-19 20:54     ` Steven Rostedt
2020-05-20  2:05       ` Matthew Wilcox
2020-05-20 10:13         ` Sebastian Andrzej Siewior
2020-05-20 10:21   ` Peter Zijlstra
2020-05-20 12:28     ` Thomas Gleixner
2020-05-19 20:19 ` [PATCH 3/8] srcu: Use local_lock() for per-CPU struct srcu_data access Sebastian Andrzej Siewior
2020-05-20 10:24   ` Peter Zijlstra
2020-05-20 12:06     ` Sebastian Andrzej Siewior
2020-05-20 13:27       ` Peter Zijlstra
2020-05-20 17:42       ` Joel Fernandes
2020-05-20 18:28         ` Sebastian Andrzej Siewior
2020-05-20 18:35           ` Peter Zijlstra
2020-05-20 18:44             ` Joel Fernandes
2020-05-20 18:50               ` Uladzislau Rezki
2020-05-20 18:59           ` Joel Fernandes
2020-05-20 18:43       ` Paul E. McKenney
2020-05-22 15:12         ` Sebastian Andrzej Siewior
2020-05-22 17:39           ` Paul E. McKenney
2020-05-23 15:08             ` Sebastian Andrzej Siewior
2020-05-23 16:59               ` Paul E. McKenney
2020-05-24 19:03               ` Sebastian Andrzej Siewior
2020-05-25  3:27                 ` Paul E. McKenney
2020-05-26 13:41                   ` [PATCH] srcu: Avoid local_irq_save() before acquiring spinlock_t Sebastian Andrzej Siewior
2020-05-26 16:16                     ` Paul E. McKenney
2020-05-26 16:31                       ` Sebastian Andrzej Siewior
2020-05-19 20:19 ` [PATCH 4/8] mm/swap: Use local_lock for protection Sebastian Andrzej Siewior
2020-05-19 23:58   ` Andrew Morton
2020-05-20  2:17     ` Matthew Wilcox
2020-05-20 10:53   ` Peter Zijlstra
2020-05-19 20:19 ` [PATCH 5/8] squashfs: make use of local lock in multi_cpu decompressor Sebastian Andrzej Siewior
2020-05-20 10:56   ` Peter Zijlstra
2020-05-19 20:19 ` [PATCH 6/8] connector/cn_proc: Protect send_msg() with a local lock Sebastian Andrzej Siewior
2020-05-20 11:03   ` Peter Zijlstra
2020-05-19 20:19 ` [PATCH 7/8] zram: Use local lock to protect per-CPU data Sebastian Andrzej Siewior
2020-05-20 11:07   ` Peter Zijlstra
2020-05-19 20:19 ` [PATCH 8/8] mm/zswap: " Sebastian Andrzej Siewior
2020-05-19 21:46   ` Song Bao Hua
2020-05-20 10:26     ` Sebastian Andrzej Siewior
2020-05-20 11:13       ` Song Bao Hua
2020-05-20 11:57         ` Sebastian Andrzej Siewior
2020-05-20 12:01           ` Song Bao Hua

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