From: Byungchul Park <byungchul.park@lge.com>
To: Nilay Vaish <nilayvaish@gmail.com>
Cc: peterz@infradead.org, mingo@kernel.org, tglx@linutronix.de,
walken@google.com, boqun.feng@gmail.com, kirill@shutemov.name,
Linux Kernel list <linux-kernel@vger.kernel.org>,
linux-mm@kvack.org, iamjoonsoo.kim@lge.com,
akpm@linux-foundation.org, npiggin@gmail.com
Subject: Re: [PATCH v3 03/15] lockdep: Refactor lookup_chain_cache()
Date: Mon, 19 Sep 2016 12:05:58 +0900 [thread overview]
Message-ID: <20160919030558.GI2279@X58A-UD3R> (raw)
In-Reply-To: <CACbG308kitsX23FTCJiUDVpN2uusabHiN1ifao53yR5fM4Z7VA@mail.gmail.com>
On Thu, Sep 15, 2016 at 10:33:46AM -0500, Nilay Vaish wrote:
> On 13 September 2016 at 04:45, Byungchul Park <byungchul.park@lge.com> wrote:
> > @@ -2215,6 +2178,75 @@ cache_hit:
> > return 1;
> > }
> >
> > +/*
> > + * Look up a dependency chain.
> > + */
> > +static inline struct lock_chain *lookup_chain_cache(u64 chain_key)
> > +{
> > + struct hlist_head *hash_head = chainhashentry(chain_key);
> > + struct lock_chain *chain;
> > +
> > + /*
> > + * We can walk it lock-free, because entries only get added
> > + * to the hash:
> > + */
> > + hlist_for_each_entry_rcu(chain, hash_head, entry) {
> > + if (chain->chain_key == chain_key) {
> > + debug_atomic_inc(chain_lookup_hits);
> > + return chain;
> > + }
> > + }
> > + return NULL;
> > +}
>
> Byungchul, do you think we should increment chain_lookup_misses
> before returning NULL from the above function?
Hello,
No, I don't think so.
It will be done in add_chain_cache().
Thank you,
Byungchul
>
> --
> Nilay
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WARNING: multiple messages have this Message-ID (diff)
From: Byungchul Park <byungchul.park@lge.com>
To: Nilay Vaish <nilayvaish@gmail.com>
Cc: peterz@infradead.org, mingo@kernel.org, tglx@linutronix.de,
walken@google.com, boqun.feng@gmail.com, kirill@shutemov.name,
Linux Kernel list <linux-kernel@vger.kernel.org>,
linux-mm@kvack.org, iamjoonsoo.kim@lge.com,
akpm@linux-foundation.org, npiggin@gmail.com
Subject: Re: [PATCH v3 03/15] lockdep: Refactor lookup_chain_cache()
Date: Mon, 19 Sep 2016 12:05:58 +0900 [thread overview]
Message-ID: <20160919030558.GI2279@X58A-UD3R> (raw)
In-Reply-To: <CACbG308kitsX23FTCJiUDVpN2uusabHiN1ifao53yR5fM4Z7VA@mail.gmail.com>
On Thu, Sep 15, 2016 at 10:33:46AM -0500, Nilay Vaish wrote:
> On 13 September 2016 at 04:45, Byungchul Park <byungchul.park@lge.com> wrote:
> > @@ -2215,6 +2178,75 @@ cache_hit:
> > return 1;
> > }
> >
> > +/*
> > + * Look up a dependency chain.
> > + */
> > +static inline struct lock_chain *lookup_chain_cache(u64 chain_key)
> > +{
> > + struct hlist_head *hash_head = chainhashentry(chain_key);
> > + struct lock_chain *chain;
> > +
> > + /*
> > + * We can walk it lock-free, because entries only get added
> > + * to the hash:
> > + */
> > + hlist_for_each_entry_rcu(chain, hash_head, entry) {
> > + if (chain->chain_key == chain_key) {
> > + debug_atomic_inc(chain_lookup_hits);
> > + return chain;
> > + }
> > + }
> > + return NULL;
> > +}
>
> Byungchul, do you think we should increment chain_lookup_misses
> before returning NULL from the above function?
Hello,
No, I don't think so.
It will be done in add_chain_cache().
Thank you,
Byungchul
>
> --
> Nilay
next prev parent reply other threads:[~2016-09-19 3:09 UTC|newest]
Thread overview: 98+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-13 9:44 [PATCH v3 00/15] lockdep: Implement crossrelease feature Byungchul Park
2016-09-13 9:44 ` Byungchul Park
2016-09-13 9:45 ` [PATCH v3 01/15] x86/dumpstack: Optimize save_stack_trace Byungchul Park
2016-09-13 9:45 ` Byungchul Park
2016-09-13 13:18 ` Josh Poimboeuf
2016-09-13 13:18 ` Josh Poimboeuf
2016-09-13 14:54 ` Byungchul Park
2016-09-13 14:54 ` Byungchul Park
2016-09-13 9:45 ` [PATCH v3 02/15] x86/dumpstack: Add save_stack_trace()_fast() Byungchul Park
2016-09-13 9:45 ` Byungchul Park
2016-09-13 13:20 ` Josh Poimboeuf
2016-09-13 13:20 ` Josh Poimboeuf
2016-09-13 9:45 ` [PATCH v3 03/15] lockdep: Refactor lookup_chain_cache() Byungchul Park
2016-09-13 9:45 ` Byungchul Park
2016-09-15 15:33 ` Nilay Vaish
2016-09-15 15:33 ` Nilay Vaish
2016-09-19 3:05 ` Byungchul Park [this message]
2016-09-19 3:05 ` Byungchul Park
2016-09-19 16:36 ` Nilay Vaish
2016-09-19 16:36 ` Nilay Vaish
2016-09-20 2:00 ` Byungchul Park
2016-09-20 2:00 ` Byungchul Park
2016-09-13 9:45 ` [PATCH v3 04/15] lockdep: Add a function building a chain between two classes Byungchul Park
2016-09-13 9:45 ` Byungchul Park
2016-09-13 9:45 ` [PATCH v3 05/15] lockdep: Make check_prev_add can use a separate stack_trace Byungchul Park
2016-09-13 9:45 ` Byungchul Park
2016-09-13 9:45 ` [PATCH v3 06/15] lockdep: Make save_trace can skip stack tracing of the current Byungchul Park
2016-09-13 9:45 ` Byungchul Park
2016-09-13 9:45 ` [PATCH v3 07/15] lockdep: Implement crossrelease feature Byungchul Park
2016-09-13 9:45 ` Byungchul Park
2016-09-13 10:05 ` Peter Zijlstra
2016-09-13 10:05 ` Peter Zijlstra
2016-09-13 12:09 ` Peter Zijlstra
2016-09-13 12:09 ` Peter Zijlstra
2016-09-13 15:14 ` Byungchul Park
2016-09-13 15:14 ` Byungchul Park
2016-09-13 15:05 ` Peter Zijlstra
2016-09-13 15:05 ` Peter Zijlstra
2016-09-13 17:12 ` Byungchul Park
2016-09-13 17:12 ` Byungchul Park
2016-09-13 19:38 ` Peter Zijlstra
2016-09-13 19:38 ` Peter Zijlstra
2016-09-13 21:42 ` Peter Zijlstra
2016-09-13 21:42 ` Peter Zijlstra
2016-09-14 1:01 ` Byungchul Park
2016-09-14 1:01 ` Byungchul Park
2016-09-14 2:27 ` Byungchul Park
2016-09-14 2:27 ` Byungchul Park
2016-09-14 4:49 ` Byungchul Park
2016-09-14 4:49 ` Byungchul Park
2016-09-14 8:11 ` Peter Zijlstra
2016-09-14 8:11 ` Peter Zijlstra
2016-09-19 2:41 ` Byungchul Park
2016-09-19 2:41 ` Byungchul Park
2016-09-19 8:50 ` Peter Zijlstra
2016-09-19 8:50 ` Peter Zijlstra
2016-09-20 5:50 ` Byungchul Park
2016-09-20 5:50 ` Byungchul Park
2016-09-20 6:26 ` Byungchul Park
2016-09-20 6:26 ` Byungchul Park
2016-09-21 1:37 ` Byungchul Park
2016-09-21 1:37 ` Byungchul Park
2016-09-22 2:57 ` Byungchul Park
2016-09-22 2:57 ` Byungchul Park
2016-09-13 9:45 ` [PATCH v3 08/15] lockdep: Make crossrelease use save_stack_trace_fast() Byungchul Park
2016-09-13 9:45 ` Byungchul Park
2016-09-13 9:45 ` [PATCH v3 09/15] lockdep: Make print_circular_bug() crosslock-aware Byungchul Park
2016-09-13 9:45 ` Byungchul Park
2016-09-13 9:45 ` [PATCH v3 10/15] lockdep: Apply crossrelease to completion operation Byungchul Park
2016-09-13 9:45 ` Byungchul Park
2016-09-13 9:45 ` [PATCH v3 11/15] pagemap.h: Remove trailing white space Byungchul Park
2016-09-13 9:45 ` Byungchul Park
2016-09-13 9:45 ` [PATCH v3 12/15] lockdep: Apply crossrelease to PG_locked lock Byungchul Park
2016-09-13 9:45 ` Byungchul Park
2016-09-13 9:45 ` [PATCH v3 13/15] lockdep: Apply lock_acquire(release) on __Set(__Clear)PageLocked Byungchul Park
2016-09-13 9:45 ` Byungchul Park
2016-09-13 9:45 ` [PATCH v3 14/15] lockdep: Move data used in CONFIG_LOCKDEP_PAGELOCK from page to page_ext Byungchul Park
2016-09-13 9:45 ` Byungchul Park
2016-09-13 9:45 ` [PATCH v3 15/15] lockdep: Crossrelease feature documentation Byungchul Park
2016-09-13 9:45 ` Byungchul Park
2016-09-15 17:25 ` Nilay Vaish
2016-09-15 17:25 ` Nilay Vaish
2016-09-19 2:59 ` Byungchul Park
2016-09-19 2:59 ` Byungchul Park
2016-09-16 15:47 ` Nilay Vaish
2016-09-16 15:47 ` Nilay Vaish
2016-09-19 3:00 ` Byungchul Park
2016-09-19 3:00 ` Byungchul Park
2016-09-20 5:00 ` Byungchul Park
2016-09-20 5:00 ` Byungchul Park
2016-09-13 9:58 ` [FYI] Output of 'cat /proc/lockdep' after applying crossrelease Byungchul Park
2016-09-13 9:58 ` Byungchul Park
2016-11-02 5:42 ` [REVISED DOC on v3] Crossrelease Lockdep Byungchul Park
2016-11-02 5:42 ` Byungchul Park
2016-11-03 8:18 ` Byungchul Park
2016-11-03 8:18 ` Byungchul Park
2016-11-08 2:54 ` Byungchul Park
2016-11-08 2:54 ` Byungchul Park
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