All of lore.kernel.org
 help / color / mirror / Atom feed
From: Richard Weinberger <richard@nod.at>
To: Adrian Hunter <adrian.hunter@intel.com>
Cc: dedekind1@gmail.com, linux-kernel@vger.kernel.org,
	Heinz.Egger@linutronix.de, linux-mtd@lists.infradead.org,
	tim.bird@am.sony.com, tglx@linutronix.de
Subject: Re: [PATCH] [RFC] UBI: Implement Fastmap support
Date: Fri, 01 Jun 2012 10:00:14 +0200	[thread overview]
Message-ID: <4FC8768E.1010703@nod.at> (raw)
In-Reply-To: <4FC85780.9070200@intel.com>

[-- Attachment #1: Type: text/plain, Size: 739 bytes --]

Am 01.06.2012 07:47, schrieb Adrian Hunter:
> It looks like, if you lose power at this point, the old fastmap may have
> been erased but the new fastmap has not been written.  That would mean
> you lose the fastmap.  Is that correct?  I guess you need to write the
> new fastmap first and then erase the old one.

True. But why is this a problem?
If we can recovers using a full scan after a power cut we are fine.
By deleting the old fastmap after writing the new one we may run out of free PEBs.
E.g: Assume a fastmap needs 4 PEBs and we have only 2 PEBs available the current approach works fine
because after returning and deleting the old fastmap we have 6 PEBs available and can write the new one.

Thanks,
//richard


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 490 bytes --]

WARNING: multiple messages have this Message-ID (diff)
From: Richard Weinberger <richard@nod.at>
To: Adrian Hunter <adrian.hunter@intel.com>
Cc: linux-mtd@lists.infradead.org, tglx@linutronix.de,
	dedekind1@gmail.com, linux-kernel@vger.kernel.org,
	Heinz.Egger@linutronix.de, tim.bird@am.sony.com
Subject: Re: [PATCH] [RFC] UBI: Implement Fastmap support
Date: Fri, 01 Jun 2012 10:00:14 +0200	[thread overview]
Message-ID: <4FC8768E.1010703@nod.at> (raw)
In-Reply-To: <4FC85780.9070200@intel.com>

[-- Attachment #1: Type: text/plain, Size: 739 bytes --]

Am 01.06.2012 07:47, schrieb Adrian Hunter:
> It looks like, if you lose power at this point, the old fastmap may have
> been erased but the new fastmap has not been written.  That would mean
> you lose the fastmap.  Is that correct?  I guess you need to write the
> new fastmap first and then erase the old one.

True. But why is this a problem?
If we can recovers using a full scan after a power cut we are fine.
By deleting the old fastmap after writing the new one we may run out of free PEBs.
E.g: Assume a fastmap needs 4 PEBs and we have only 2 PEBs available the current approach works fine
because after returning and deleting the old fastmap we have 6 PEBs available and can write the new one.

Thanks,
//richard


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 490 bytes --]

  reply	other threads:[~2012-06-01  8:00 UTC|newest]

Thread overview: 68+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-05-23 11:06 [RFC v7] UBI: Fastmap support (aka checkpointing) Richard Weinberger
2012-05-23 11:06 ` Richard Weinberger
2012-05-23 11:06 ` [PATCH] [RFC] UBI: Implement Fastmap support Richard Weinberger
2012-05-23 11:06   ` Richard Weinberger
2012-05-26 13:22   ` Artem Bityutskiy
2012-05-26 13:22     ` Artem Bityutskiy
2012-05-31 10:37   ` Adrian Hunter
2012-05-31 10:37     ` Adrian Hunter
2012-05-31 13:31     ` Richard Weinberger
2012-05-31 13:31       ` Richard Weinberger
2012-06-01  5:47   ` Adrian Hunter
2012-06-01  5:47     ` Adrian Hunter
2012-06-01  8:00     ` Richard Weinberger [this message]
2012-06-01  8:00       ` Richard Weinberger
2012-06-01  8:10       ` Artem Bityutskiy
2012-06-01  8:10         ` Artem Bityutskiy
2012-06-01  8:10         ` Richard Weinberger
2012-06-01  8:10           ` Richard Weinberger
2012-06-01  8:47           ` Adrian Hunter
2012-06-01  8:47             ` Adrian Hunter
2012-05-26 12:41 ` [RFC v7] UBI: Fastmap support (aka checkpointing) Artem Bityutskiy
2012-05-26 12:41   ` Artem Bityutskiy
2012-05-26 14:01   ` Richard Weinberger
2012-05-26 14:01     ` Richard Weinberger
2012-05-26 14:15     ` Artem Bityutskiy
2012-05-26 14:15       ` Artem Bityutskiy
2012-05-28  6:36   ` Shmulik Ladkani
2012-05-28  6:36     ` Shmulik Ladkani
2012-05-28  6:46     ` Artem Bityutskiy
2012-05-28  6:46       ` Artem Bityutskiy
2012-05-28  9:49       ` Richard Weinberger
2012-05-28  9:49         ` Richard Weinberger
  -- strict thread matches above, loose matches on Subject: below --
2012-05-21 14:01 [RFC v6] " Richard Weinberger
2012-05-21 14:01 ` [PATCH] [RFC] UBI: Implement Fastmap support Richard Weinberger
2012-05-21 14:01   ` Richard Weinberger
2012-05-22 13:43   ` Artem Bityutskiy
2012-05-22 13:43     ` Artem Bityutskiy
2012-05-22 15:01   ` Shmulik Ladkani
2012-05-22 15:01     ` Shmulik Ladkani
2012-05-22 16:55     ` Richard Weinberger
2012-05-22 16:55       ` Richard Weinberger
2012-05-22 18:18       ` Shmulik Ladkani
2012-05-22 18:18         ` Shmulik Ladkani
2012-05-22 18:57         ` Richard Weinberger
2012-05-22 18:57           ` Richard Weinberger
2012-05-23  6:18           ` Shmulik Ladkani
2012-05-23  6:18             ` Shmulik Ladkani
2012-05-23  7:43             ` Richard Weinberger
2012-05-23  7:43               ` Richard Weinberger
2012-05-22 20:11         ` Richard Weinberger
2012-05-22 20:11           ` Richard Weinberger
2012-05-24  8:19           ` Artem Bityutskiy
2012-05-24  8:19             ` Artem Bityutskiy
2012-05-24  8:26             ` Richard Weinberger
2012-05-24  8:26               ` Richard Weinberger
2012-05-24  9:21               ` Artem Bityutskiy
2012-05-24  9:21                 ` Artem Bityutskiy
2012-05-24  8:17       ` Artem Bityutskiy
2012-05-24  8:17         ` Artem Bityutskiy
2012-05-24  9:56         ` Shmulik Ladkani
2012-05-24  9:56           ` Shmulik Ladkani
2012-05-24 10:03           ` Richard Weinberger
2012-05-24 10:03             ` Richard Weinberger
2012-05-24 20:07             ` Shmulik Ladkani
2012-05-24 20:07               ` Shmulik Ladkani
2012-05-24  8:22       ` Artem Bityutskiy
2012-05-24  8:22         ` Artem Bityutskiy
2012-05-24  8:24         ` Richard Weinberger
2012-05-24  8:24           ` Richard Weinberger

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=4FC8768E.1010703@nod.at \
    --to=richard@nod.at \
    --cc=Heinz.Egger@linutronix.de \
    --cc=adrian.hunter@intel.com \
    --cc=dedekind1@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mtd@lists.infradead.org \
    --cc=tglx@linutronix.de \
    --cc=tim.bird@am.sony.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.