From: "Maciej Żenczykowski" <zenczykowski@gmail.com>
To: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: Florian Westphal <fw@strlen.de>,
Linux Network Development Mailing List <netdev@vger.kernel.org>,
Netfilter Development Mailing List
<netfilter-devel@vger.kernel.org>
Subject: Re: [PATCH] iptables: flush stdout after every verbose log.
Date: Mon, 27 Apr 2020 17:14:24 -0700 [thread overview]
Message-ID: <CAHo-OoxP6ZrvbXFH_tC9_wdVDg7y=8bzVY9oKZTieZL_mqS1NQ@mail.gmail.com> (raw)
In-Reply-To: <20200428000525.GD24002@salvia>
> Could you check if this slows down iptables-restore?
per the iptables-restore man page
-v, --verbose
Print additional debug info during ruleset processing.
Well, if you run it with verbose mode enabled you probably don't care
about performance all that much...
And it only does anything if you're feeding in comments, which again -
is unlikely.
iptables-save produces two comment lines per table, so you're likely
to have a grand total of 8 of these lines
(if you have raw/nat/mangle/filter tables all listed), and if you feed
that in to iptables-restore -v then
you end up calling flush 8 times, which triggers 8 extra write()
syscalls - which aren't exactly expensive to begin with...
So I think this is a non issue.
(I could change it so that only "#PING" flushes, which is the actual
comment netd sends for healthchecking,
but I just don't think it matters)
next prev parent reply other threads:[~2020-04-28 0:14 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-21 8:15 [PATCH] iptables: flush stdout after every verbose log Maciej Żenczykowski
2020-04-28 0:05 ` Pablo Neira Ayuso
2020-04-28 0:14 ` Maciej Żenczykowski [this message]
2020-04-28 22:30 ` Pablo Neira Ayuso
2020-05-09 19:30 ` Maciej Żenczykowski
2020-05-11 12:10 ` Pablo Neira Ayuso
2020-05-11 15:40 ` Maciej Żenczykowski
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='CAHo-OoxP6ZrvbXFH_tC9_wdVDg7y=8bzVY9oKZTieZL_mqS1NQ@mail.gmail.com' \
--to=zenczykowski@gmail.com \
--cc=fw@strlen.de \
--cc=netdev@vger.kernel.org \
--cc=netfilter-devel@vger.kernel.org \
--cc=pablo@netfilter.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.