From: gmate.amit@gmail.com (Kumar amit mehta)
To: kernelnewbies@lists.kernelnewbies.org
Subject: block layer: request unplugging threshold: unplug_thresh
Date: Tue, 2 Jul 2013 11:06:46 -0700 [thread overview]
Message-ID: <20130702180646.GA1572@gmail.com> (raw)
Hi,
While trying to understand the block layer in Linux, I stumbled upon this
request(struct request) unplugging threshold(q->unplug_thresh), which is
hardcoded to '4'. So far, my understanding is that there could be explicit
request unplugging(e.g. multipath module registering it's unplug_fn and later
calling blk_unplug) as well as implicit ones(either due to timeout or
read/write request threshold reaching to unplug_thresh.
So having, q->unplug_thresh = 4 (ref. blk_queue_make_request), seem like a very
small value and even if it's not, then why shouldn't the driver such as RAID
framework(dm/md), be allowed to manipulate this threshold value ?
-Amit
reply other threads:[~2013-07-02 18:06 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
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=20130702180646.GA1572@gmail.com \
--to=gmate.amit@gmail.com \
--cc=kernelnewbies@lists.kernelnewbies.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 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.