From: Jan Kara <jack@suse.cz>
To: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>,
mingo@kernel.org, peterz@infradead.org,
akpm@linux-foundation.org, jack@suse.cz,
kirill.shutemov@linux.intel.com, mhocko@suse.com,
mgorman@techsingularity.net, linux-kernel@vger.kernel.org,
Davidlohr Bueso <dbueso@suse.de>
Subject: Re: [PATCH 2/6] locking: Introduce range reader/writer lock
Date: Thu, 13 Apr 2017 10:38:17 +0200 [thread overview]
Message-ID: <20170413083817.GC21025@quack2.suse.cz> (raw)
In-Reply-To: <f9ecb1f6-50da-1272-dfee-02c34edd0db3@linux.vnet.ibm.com>
On Thu 13-04-17 10:07:48, Laurent Dufour wrote:
> On 06/04/2017 18:50, Davidlohr Bueso wrote:
> > On Thu, 06 Apr 2017, Laurent Dufour wrote:
> >
> >> How is 'seqnum' wrapping handled here ?
> >> I'd rather see something like time_before() here, isn't it ?
> >
> > Its a 64bit counter, no overflows.
>
> I should have miss something, what prevents this 64bit counter to not
> overflow ?
> At some point of time, this counter could reach ~0UL and then 0UL, which
> is breaking this check.
Count for yourself how long would it take for the counter to overflow if we
incremented it say every nanosecond?
Honza
--
Jan Kara <jack@suse.com>
SUSE Labs, CR
next prev parent reply other threads:[~2017-04-13 8:38 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-06 8:46 [PATCH v2 -tip 0/6] " Davidlohr Bueso
2017-04-06 8:46 ` [PATCH 1/6] interval-tree: Build unconditionally Davidlohr Bueso
2017-04-06 8:46 ` [PATCH 2/6] locking: Introduce range reader/writer lock Davidlohr Bueso
2017-04-06 9:01 ` Laurent Dufour
2017-04-06 16:50 ` Davidlohr Bueso
2017-04-13 8:07 ` Laurent Dufour
2017-04-13 8:38 ` Jan Kara [this message]
2017-04-13 8:58 ` Laurent Dufour
2017-04-06 10:24 ` Peter Zijlstra
2017-04-18 13:57 ` Laurent Dufour
2017-04-20 16:01 ` Davidlohr Bueso
2017-04-21 7:00 ` Laurent Dufour
2017-04-06 8:46 ` [PATCH 3/6] locking/locktorture: Fix rwsem reader_delay Davidlohr Bueso
2017-04-06 8:46 ` [PATCH 4/6] locking/locktorture: Fix num reader/writer corner cases Davidlohr Bueso
2017-04-06 8:46 ` [PATCH 5/6] locking/locktorture: Support range rwlocks Davidlohr Bueso
2017-04-06 8:46 ` [PATCH 6/6] staging/lustre: Use generic range rwlock Davidlohr Bueso
2017-04-07 10:08 ` Dilger, Andreas
2017-04-19 12:37 ` [PATCH v2 -tip 0/6] locking: Introduce range reader/writer lock Peter Zijlstra
2017-04-20 17:13 ` Davidlohr Bueso
2017-04-20 17:53 ` Peter Zijlstra
2017-04-20 18:36 ` Davidlohr Bueso
2017-04-20 19:10 ` Peter Zijlstra
2017-05-15 9:19 ` Davidlohr Bueso
2017-05-15 9:07 [PATCH v3 " Davidlohr Bueso
2017-05-15 9:07 ` [PATCH 2/6] " Davidlohr Bueso
2017-05-15 13:02 ` Peter Zijlstra
2017-05-16 22:19 ` Davidlohr Bueso
2017-05-15 13:44 ` Peter Zijlstra
2017-05-16 21:17 ` Davidlohr Bueso
2017-05-15 13:59 ` Peter Zijlstra
2017-05-23 15:12 ` Laurent Dufour
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=20170413083817.GC21025@quack2.suse.cz \
--to=jack@suse.cz \
--cc=akpm@linux-foundation.org \
--cc=dave@stgolabs.net \
--cc=dbueso@suse.de \
--cc=kirill.shutemov@linux.intel.com \
--cc=ldufour@linux.vnet.ibm.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mgorman@techsingularity.net \
--cc=mhocko@suse.com \
--cc=mingo@kernel.org \
--cc=peterz@infradead.org \
/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
Powered by JetHome