From: Dominique Martinet <email@example.com>
To: Eric Van Hensbergen <firstname.lastname@example.org>
Cc: Latchesar Ionkov <email@example.com>,
V9FS Developers <firstname.lastname@example.org>,
David Miller <email@example.com>
Subject: Re: [V9fs-developer] [PATCH] net: trans_rdma: remove unused function
Date: Fri, 26 Jul 2013 09:01:38 +0200 [thread overview]
Message-ID: <20130726070138.GA28421@nautica> (raw)
I think I need to stop sending mails before triple-checking things!
So sorry for the multiple mails again.
Dominique Martinet wrote on Thu, Jul 25, 2013 :
> There is one problem though - if the server handles the original request
> before getting the flush, the receive buffer will be consumed and we
> won't send a new one, so we'll starve the reception queue.
> I'm afraid I don't have any bright idea there...
This still looks correct to me.
> While we are on reception buffer issues, there is another problem with
> the queue of receive buffers, even without flush, in the following
> - post a buffer for tag 0, on a hanging request
> - post a buffer for tag 1
> - reply for tag 1 will come on buffer from tag 0
> - post another request with tag 1.. the buffer already is in the queue,
> and we don't know we can post the buffer associated with tag 0 back.
It actually looks like the reply buffers are swapped properly - taken
out of the req struct into the context on send, then given back to the
appropriate req on reception, so on normal operation there's no problem
with what I described - sorry for crying wolf.
> I haven't found how to reproduce this perfectly yet, but a dd with
> blocksize 1MB and one with blocksize 10B in parallel brought the
> mountpoint down (and the whole server was completely unavailable for the
> duration of the dd - TCP sessions timed out, I even got IO errors on the
> local disk :D)
I need to run more tests to explain what happens with the two dds, but
it's easily reproductible with debugs on, I guess that helps with a race
next prev parent reply other threads:[~2013-07-26 7:01 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-22 12:59 [PATCH] net: trans_rdma: remove unused function Andi Shyti
2013-07-24 22:46 ` David Miller
2013-07-24 23:09 ` Paul Bolle
2013-07-24 23:45 ` David Miller
2013-07-25 6:14 ` [V9fs-developer] " Dominique Martinet
2013-07-25 6:48 ` Dominique Martinet
2013-07-25 8:27 ` Andi Shyti
2013-07-25 8:35 ` David Miller
[not found] ` <CAFkjPTm1FH24EfWMDrXTh7DmU8WAb0ji-jkUgkayqMzfWj9O0A@mail.gmail.com>
2013-07-25 19:05 ` Dominique Martinet
2013-07-26 7:01 ` Dominique Martinet [this message]
[not found] ` <CAFkjPTkr5JYf6qc=pjcG8rSoocFekU-cTw450SujTvpCp33cyw@mail.gmail.com>
2013-07-26 15:17 ` Dominique Martinet
2013-07-25 8:54 ` [PATCH] 9p: client: remove unused code and any reference to "cancelled" function Andi Shyti
2013-07-25 8:57 ` Andi Shyti
2013-07-30 22:54 ` David Miller
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:
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
* 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).