linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Tanya Brokhman <tlinder@codeaurora.org>
To: Richard Weinberger <richard@nod.at>,
	"Bityutskiy, Artem" <artem.bityutskiy@intel.com>
Cc: "linux-mtd@lists.infradead.org" <linux-mtd@lists.infradead.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"dedekind1@gmail.com" <dedekind1@gmail.com>
Subject: Re: [PATCH 4/4] UBI: Fastmap: Ensure that only one fastmap work is scheduled
Date: Thu, 02 Oct 2014 17:22:41 +0300	[thread overview]
Message-ID: <542D5FB1.3090307@codeaurora.org> (raw)
In-Reply-To: <542A5F64.5000302@nod.at>

On 9/30/2014 10:44 AM, Richard Weinberger wrote:
> Am 30.09.2014 09:39, schrieb Bityutskiy, Artem:
>> On Tue, 2014-09-30 at 08:59 +0200, Richard Weinberger wrote:
>>> Am 30.09.2014 08:45, schrieb Bityutskiy, Artem:
>>>> On Tue, 2014-09-30 at 00:20 +0200, Richard Weinberger wrote:
>>>>> +       spin_lock(&ubi->wl_lock);
>>>>> +       ubi->fm_work_scheduled = 0;
>>>>> +       spin_unlock(&ubi->wl_lock);
>>>>
>>>> Andrew Morton once said me that if I am protecting an integer change
>>>> like this with a spinlock, I have a problem in my locking design. He was
>>>> right for my particular case.
>>>>
>>>> Integer is changes atomic. The only other thing spinlock adds are the
>>>> barriers.
>>>
>>> I've added the spinlock to have a barrier in any case.
>>
>> Examples of any?
>
> You mean a case where the compiler would reorder code and the barrier is needed?
> I don't have one, but I'm not that creative as a modern C compiler.
> If you say that no barrier is needed I'll trust you. :-)

we just implemented the same thing :) It's being tested....
Why not use atomic_t fm_work_scheduled and save the spin_lock?

>
> Thanks,
> //richard
>
>
> ______________________________________________________
> Linux MTD discussion mailing list
> http://lists.infradead.org/mailman/listinfo/linux-mtd/
>


-- 
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, 
hosted by The Linux Foundation

      reply	other threads:[~2014-10-02 14:22 UTC|newest]

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-09-29 22:20 UBI: Fastmap fixes - round one Richard Weinberger
2014-09-29 22:20 ` [PATCH 1/4] UBI: Ensure that all fastmap work is done upon WL shutdown Richard Weinberger
2014-09-30  6:26   ` Artem Bityutskiy
2014-09-30  6:58     ` Richard Weinberger
2014-09-30  7:53       ` Bityutskiy, Artem
2014-09-30  8:07         ` Richard Weinberger
2014-10-03 12:52           ` Artem Bityutskiy
2014-10-02 13:05   ` Tanya Brokhman
2014-10-02 13:18     ` Richard Weinberger
2014-09-29 22:20 ` [PATCH 2/4] UBI: Fastmap: Calc fastmap size correctly Richard Weinberger
2014-10-02 13:14   ` Tanya Brokhman
2014-10-02 13:18     ` Richard Weinberger
2014-10-02 14:04   ` Tanya Brokhman
2014-10-03 14:38   ` Artem Bityutskiy
2014-09-29 22:20 ` [PATCH 3/4] UBI: Fastmap: Care about the protection queue Richard Weinberger
2014-10-02 13:28   ` Tanya Brokhman
2014-10-02 13:32     ` Richard Weinberger
2014-10-02 14:14       ` Tanya Brokhman
2014-10-03 14:31   ` Artem Bityutskiy
2014-10-03 19:06     ` Richard Weinberger
2014-10-13 13:17       ` Artem Bityutskiy
2014-10-13 14:30         ` Richard Weinberger
2014-10-13 15:23           ` Artem Bityutskiy
2014-10-13 15:28             ` Bityutskiy, Artem
2014-10-13 21:04             ` Richard Weinberger
2014-10-14 10:23               ` Artem Bityutskiy
2014-10-14 12:21                 ` Tanya Brokhman
2014-10-14 13:02                   ` Artem Bityutskiy
2014-10-14 13:35                     ` Tanya Brokhman
2014-10-16 10:06                 ` Richard Weinberger
2014-10-16 10:15                   ` Artem Bityutskiy
2014-10-16 11:07                     ` Richard Weinberger
2014-10-20 14:46                   ` Artem Bityutskiy
2014-10-20 15:17                     ` Richard Weinberger
2014-10-20 15:40                       ` Artem Bityutskiy
2014-10-20 15:59                         ` Richard Weinberger
2014-10-20 16:09                           ` Artem Bityutskiy
2014-10-20 16:17                             ` Richard Weinberger
2014-10-20 20:46                         ` Richard Weinberger
2014-09-29 22:20 ` [PATCH 4/4] UBI: Fastmap: Ensure that only one fastmap work is scheduled Richard Weinberger
2014-09-30  6:45   ` Bityutskiy, Artem
2014-09-30  6:59     ` Richard Weinberger
2014-09-30  7:39       ` Bityutskiy, Artem
2014-09-30  7:44         ` Richard Weinberger
2014-10-02 14:22           ` Tanya Brokhman [this message]

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=542D5FB1.3090307@codeaurora.org \
    --to=tlinder@codeaurora.org \
    --cc=artem.bityutskiy@intel.com \
    --cc=dedekind1@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mtd@lists.infradead.org \
    --cc=richard@nod.at \
    /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).