From: Byungchul Park <byungchul.park@lge.com>
To: Boqun Feng <boqun.feng@gmail.com>
Cc: peterz@infradead.org, mingo@kernel.org, tglx@linutronix.de,
walken@google.com, kirill@shutemov.name,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
iamjoonsoo.kim@lge.com, akpm@linux-foundation.org,
npiggin@gmail.com
Subject: Re: [PATCH v5 01/13] lockdep: Refactor lookup_chain_cache()
Date: Thu, 19 Jan 2017 18:52:07 +0900 [thread overview]
Message-ID: <20170119095207.GP3326@X58A-UD3R> (raw)
In-Reply-To: <20170119091627.GG15084@tardis.cn.ibm.com>
On Thu, Jan 19, 2017 at 05:16:27PM +0800, Boqun Feng wrote:
> On Wed, Jan 18, 2017 at 10:17:27PM +0900, Byungchul Park wrote:
> > Currently, lookup_chain_cache() provides both 'lookup' and 'add'
> > functionalities in a function. However, each is useful. So this
> > patch makes lookup_chain_cache() only do 'lookup' functionality and
> > makes add_chain_cahce() only do 'add' functionality. And it's more
> > readable than before.
> >
> > Signed-off-by: Byungchul Park <byungchul.park@lge.com>
> > ---
> > kernel/locking/lockdep.c | 129 +++++++++++++++++++++++++++++------------------
> > 1 file changed, 81 insertions(+), 48 deletions(-)
> >
> > diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
> > index 4d7ffc0..f37156f 100644
> > --- a/kernel/locking/lockdep.c
> > +++ b/kernel/locking/lockdep.c
> > @@ -2109,15 +2109,9 @@ static int check_no_collision(struct task_struct *curr,
> > return 1;
> > }
> >
> > -/*
> > - * Look up a dependency chain. If the key is not present yet then
> > - * add it and return 1 - in this case the new dependency chain is
> > - * validated. If the key is already hashed, return 0.
> > - * (On return with 1 graph_lock is held.)
> > - */
>
> I think you'd better put some comments here for the behavior of
> add_chain_cache(), something like:
>
> /*
> * Add a dependency chain into chain hashtable.
> *
> * Must be called with graph_lock held.
> * Return 0 if fail to add the chain, and graph_lock is released.
> * Return 1 with graph_lock held if succeed.
> */
Yes. I will apply what you recommand.
Thank you very much. :)
Thanks,
Byungchul
>
> Regards,
> Boqun
>
> > -static inline int lookup_chain_cache(struct task_struct *curr,
> > - struct held_lock *hlock,
> > - u64 chain_key)
> > +static inline int add_chain_cache(struct task_struct *curr,
> > + struct held_lock *hlock,
> > + u64 chain_key)
> > {
> > struct lock_class *class = hlock_class(hlock);
> > struct hlist_head *hash_head = chainhashentry(chain_key);
> > @@ -2125,49 +2119,18 @@ static inline int lookup_chain_cache(struct task_struct *curr,
> > int i, j;
> >
> > /*
> > + * Allocate a new chain entry from the static array, and add
> > + * it to the hash:
> > + */
> > +
> > + /*
> > * We might need to take the graph lock, ensure we've got IRQs
> > * disabled to make this an IRQ-safe lock.. for recursion reasons
> > * lockdep won't complain about its own locking errors.
> > */
> > if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
> > return 0;
> [...]
next prev parent reply other threads:[~2017-01-19 10:07 UTC|newest]
Thread overview: 63+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-18 13:17 [PATCH v5 00/13] lockdep: Implement crossrelease feature Byungchul Park
2017-01-18 13:17 ` [PATCH v5 01/13] lockdep: Refactor lookup_chain_cache() Byungchul Park
2017-01-19 9:16 ` Boqun Feng
2017-01-19 9:52 ` Byungchul Park [this message]
2017-01-26 7:53 ` Byungchul Park
2017-01-18 13:17 ` [PATCH v5 02/13] lockdep: Fix wrong condition to print bug msgs for MAX_LOCKDEP_CHAIN_HLOCKS Byungchul Park
2017-01-18 13:17 ` [PATCH v5 03/13] lockdep: Add a function building a chain between two classes Byungchul Park
2017-01-18 13:17 ` [PATCH v5 04/13] lockdep: Refactor save_trace() Byungchul Park
2017-01-18 13:17 ` [PATCH v5 05/13] lockdep: Pass a callback arg to check_prev_add() to handle stack_trace Byungchul Park
2017-01-26 7:43 ` Byungchul Park
2017-01-18 13:17 ` [PATCH v5 06/13] lockdep: Implement crossrelease feature Byungchul Park
2017-02-28 12:26 ` Peter Zijlstra
2017-02-28 12:45 ` Peter Zijlstra
2017-02-28 12:49 ` Peter Zijlstra
2017-03-01 6:20 ` Byungchul Park
2017-02-28 13:05 ` Peter Zijlstra
2017-02-28 13:28 ` Byungchul Park
2017-02-28 13:35 ` Peter Zijlstra
2017-02-28 14:00 ` Byungchul Park
2017-02-28 13:10 ` Peter Zijlstra
2017-02-28 13:24 ` Byungchul Park
2017-02-28 18:29 ` Peter Zijlstra
2017-03-01 4:40 ` Byungchul Park
2017-03-01 10:45 ` Peter Zijlstra
2017-03-01 12:10 ` Byungchul Park
2017-02-28 13:40 ` Peter Zijlstra
2017-03-01 5:43 ` Byungchul Park
2017-03-01 12:28 ` Peter Zijlstra
2017-03-02 13:40 ` Peter Zijlstra
2017-03-03 0:17 ` Byungchul Park
2017-03-03 8:14 ` Peter Zijlstra
2017-03-03 9:13 ` Peter Zijlstra
2017-03-03 9:32 ` Peter Zijlstra
2017-03-05 3:33 ` Byungchul Park
2017-08-10 12:18 ` [tip:locking/core] locking/lockdep: Avoid creating redundant links tip-bot for Peter Zijlstra
2017-03-05 3:08 ` [PATCH v5 06/13] lockdep: Implement crossrelease feature Byungchul Park
2017-03-07 11:42 ` Peter Zijlstra
2017-03-03 0:39 ` Byungchul Park
2017-02-28 15:49 ` Peter Zijlstra
2017-03-01 5:17 ` Byungchul Park
2017-03-01 6:18 ` Byungchul Park
2017-03-02 2:52 ` Byungchul Park
2017-02-28 18:15 ` Peter Zijlstra
2017-03-01 7:21 ` Byungchul Park
2017-03-01 10:43 ` Peter Zijlstra
2017-03-01 12:27 ` Byungchul Park
2017-03-02 4:20 ` Matthew Wilcox
2017-03-02 4:45 ` byungchul.park
2017-03-02 14:39 ` Matthew Wilcox
2017-03-02 23:50 ` Byungchul Park
2017-03-05 8:01 ` Byungchul Park
2017-03-14 7:36 ` Byungchul Park
2017-03-02 13:41 ` Peter Zijlstra
2017-03-02 23:43 ` Byungchul Park
2017-01-18 13:17 ` [PATCH v5 07/13] lockdep: Make print_circular_bug() aware of crossrelease Byungchul Park
2017-01-18 13:17 ` [PATCH v5 08/13] lockdep: Apply crossrelease to completions Byungchul Park
2017-01-18 13:17 ` [PATCH v5 09/13] pagemap.h: Remove trailing white space Byungchul Park
2017-01-18 13:17 ` [PATCH v5 10/13] lockdep: Apply crossrelease to PG_locked locks Byungchul Park
2017-01-18 13:17 ` [PATCH v5 11/13] lockdep: Apply lock_acquire(release) on __Set(__Clear)PageLocked Byungchul Park
2017-01-18 13:17 ` [PATCH v5 12/13] lockdep: Move data of CONFIG_LOCKDEP_PAGELOCK from page to page_ext Byungchul Park
2017-01-18 13:17 ` [PATCH v5 13/13] lockdep: Crossrelease feature documentation Byungchul Park
2017-01-20 9:08 ` [REVISED DOCUMENT] " Byungchul Park
2017-02-20 8:38 ` [PATCH v5 00/13] lockdep: Implement crossrelease feature Byungchul Park
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20170119095207.GP3326@X58A-UD3R \
--to=byungchul.park@lge.com \
--cc=akpm@linux-foundation.org \
--cc=boqun.feng@gmail.com \
--cc=iamjoonsoo.kim@lge.com \
--cc=kirill@shutemov.name \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mingo@kernel.org \
--cc=npiggin@gmail.com \
--cc=peterz@infradead.org \
--cc=tglx@linutronix.de \
--cc=walken@google.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).