From: Bart Van Assche <bvanassche@acm.org>
To: Hannes Reinecke <hare@suse.de>,
James Bottomley <jbottomley@parallels.com>
Cc: Sean Stewart <sean.stewart@netapp.com>,
Martin George <marting@netapp.com>,
linux-scsi@vger.kernel.org
Subject: Re: [PATCH 16/16] scsi_dh_alua: Use workqueue for RTPG
Date: Fri, 14 Feb 2014 20:03:26 +0100 [thread overview]
Message-ID: <52FE687E.7000100@acm.org> (raw)
In-Reply-To: <1391160600-19652-17-git-send-email-hare@suse.de>
On 01/31/14 10:30, Hannes Reinecke wrote:
> +static void alua_check(struct scsi_device *sdev)
> +{
> + struct alua_dh_data *h = get_alua_data(sdev);
> + struct alua_port_group *pg;
> +
> + if (!h)
> + return;
> +
> + rcu_read_lock();
> + pg = rcu_dereference(h->pg);
> + if (pg) {
> + kref_get(&pg->kref);
> + rcu_read_unlock();
> + alua_rtpg_queue(pg, sdev, NULL);
> + kref_put(&pg->kref, release_port_group);
> + } else
> + rcu_read_unlock();
> +}
>From the implementation it seems to me like the target port group data
is kept just as long as it is in use ? Has it been considered to keep
that data as long as the sdev exists instead ? I think that would result
in far fewer reference count manipulations and hence in code that is
easier to read and to verify.
Thanks,
Bart.
next prev parent reply other threads:[~2014-02-14 19:03 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-31 9:29 [PATCHv2 00/16] scsi_dh_alua updates Hannes Reinecke
2014-01-31 9:29 ` [PATCH 01/16] scsi_dh_alua: Improve error handling Hannes Reinecke
2014-02-14 11:16 ` Bart Van Assche
2014-02-14 11:32 ` Hannes Reinecke
2014-03-06 23:43 ` Jeremy Linton
2014-03-07 7:12 ` Hannes Reinecke
2014-03-07 15:46 ` Jeremy Linton
2014-01-31 9:29 ` [PATCH 02/16] scsi_dh_alua: use flag for RTPG extended header Hannes Reinecke
2014-01-31 9:29 ` [PATCH 03/16] scsi_dh_alua: Pass buffer as function argument Hannes Reinecke
2014-02-14 11:22 ` Bart Van Assche
2014-02-14 11:36 ` Hannes Reinecke
2014-01-31 9:29 ` [PATCH 04/16] scsi_dh_alua: Make stpg synchronous Hannes Reinecke
2014-02-07 1:24 ` Mike Christie
2014-02-07 1:54 ` Mike Christie
2014-02-12 15:29 ` Hannes Reinecke
2014-02-12 16:11 ` Mike Christie
2014-02-12 16:26 ` Mike Christie
2014-02-12 17:31 ` Mike Christie
2014-02-13 9:31 ` Hannes Reinecke
2014-02-14 11:37 ` Bart Van Assche
2014-02-14 11:53 ` Hannes Reinecke
2014-02-14 18:21 ` Mike Christie
2014-02-19 8:09 ` Hannes Reinecke
2014-02-14 17:17 ` Mike Christie
2014-02-14 11:27 ` Bart Van Assche
2014-02-14 11:38 ` Hannes Reinecke
2014-01-31 9:29 ` [PATCH 05/16] scsi_dh_alua: put sense buffer on stack Hannes Reinecke
2014-01-31 9:29 ` [PATCH 06/16] scsi_dh_alua: use local buffer for VPD inquiry Hannes Reinecke
2014-02-13 9:51 ` Maurizio Lombardi
2014-02-13 10:10 ` Hannes Reinecke
2014-02-14 11:41 ` Bart Van Assche
2014-01-31 9:29 ` [PATCH 07/16] scsi_dh_alua: Use separate alua_port_group structure Hannes Reinecke
2014-02-14 11:56 ` Bart Van Assche
2014-02-14 12:16 ` Hannes Reinecke
2014-02-14 16:12 ` Hannes Reinecke
2014-02-14 17:42 ` Bart Van Assche
2014-01-31 9:29 ` [PATCH 08/16] scsi_dh_alua: parse target device id Hannes Reinecke
2014-02-14 12:09 ` Bart Van Assche
2014-02-14 12:21 ` Hannes Reinecke
2014-02-17 14:05 ` Bart Van Assche
2014-02-17 14:09 ` Hannes Reinecke
2014-02-17 14:27 ` Bart Van Assche
2014-02-17 14:33 ` Hannes Reinecke
2014-02-18 7:26 ` Bart Van Assche
2014-01-31 9:29 ` [PATCH 09/16] scsi_dh_alua: simplify sense code handling Hannes Reinecke
2014-01-31 9:29 ` [PATCH 10/16] scsi_dh_alua: Do not attach to management devices Hannes Reinecke
2014-01-31 9:29 ` [PATCH 11/16] scsi_dh_alua: multipath failover fails with error 15 Hannes Reinecke
2015-03-30 12:30 ` Bart Van Assche
2015-03-30 12:32 ` Hannes Reinecke
2014-01-31 9:29 ` [PATCH 12/16] scsi_dh: return individual errors in scsi_dh_activate() Hannes Reinecke
2014-01-31 9:29 ` [PATCH 13/16] scsi_dh_alua: Clarify logging message Hannes Reinecke
2014-01-31 9:29 ` [PATCH 14/16] scsi_dh: invoke callback if ->activate is not present Hannes Reinecke
2014-01-31 9:29 ` [PATCH 15/16] scsi_dh_alua: revert commit a8e5a2d593cbfccf530c3382c2c328d2edaa7b66 Hannes Reinecke
2014-01-31 9:30 ` [PATCH 16/16] scsi_dh_alua: Use workqueue for RTPG Hannes Reinecke
2014-02-14 19:03 ` Bart Van Assche [this message]
2014-04-29 21:47 ` Stewart, Sean
2014-05-08 7:04 ` Hannes Reinecke
2014-03-02 9:10 ` [PATCHv2 00/16] scsi_dh_alua updates Bart Van Assche
-- strict thread matches above, loose matches on Subject: below --
2013-12-20 12:13 [PATCH " Hannes Reinecke
2013-12-20 12:13 ` [PATCH 16/16] scsi_dh_alua: Use workqueue for RTPG Hannes Reinecke
2014-01-21 8:25 ` Vaughan Cao
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=52FE687E.7000100@acm.org \
--to=bvanassche@acm.org \
--cc=hare@suse.de \
--cc=jbottomley@parallels.com \
--cc=linux-scsi@vger.kernel.org \
--cc=marting@netapp.com \
--cc=sean.stewart@netapp.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).