linux-api.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Willy Tarreau <w@1wt.eu>
To: "Ahmed S. Darwish" <darwish.07@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
	Lennart Poettering <mzxreary@0pointer.de>,
	"Theodore Y. Ts'o" <tytso@mit.edu>,
	"Eric W. Biederman" <ebiederm@xmission.com>,
	"Alexander E. Patrakov" <patrakov@gmail.com>,
	Michael Kerrisk <mtk.manpages@gmail.com>,
	Matthew Garrett <mjg59@srcf.ucam.org>,
	lkml <linux-kernel@vger.kernel.org>,
	linux-ext4@vger.kernel.org, linux-api@vger.kernel.org,
	linux-man@vger.kernel.org
Subject: Re: [PATCH RFC v4 1/1] random: WARN on large getrandom() waits and introduce getrandom2()
Date: Fri, 20 Sep 2019 19:26:09 +0200	[thread overview]
Message-ID: <20190920172609.GA1832@1wt.eu> (raw)
In-Reply-To: <20190920134609.GA2113@pc>

Hi Ahmed,

On Fri, Sep 20, 2019 at 03:46:09PM +0200, Ahmed S. Darwish wrote:
> Problem is, glibc is still *really* slow in adopting linux syscall
> wrappers, so I'm not optimistic about that...
>
> I still see the new system call as the sanest path, even provided
> the cost of a new syscall number..

New syscalls are always a pain to deal with in userland, because when
they are introduced, everyone wants them long before they're available
in glibc. So userland has to define NR_xxx for each supported arch and
to perform the call itself.

With flags adoption is instantaneous. Just #ifndef/#define, check if
the flag is supported and that's done. The only valid reason for a new
syscall is when the API changes (e.g. one extra arg, a la accept4()),
which doesn't seem to be the case here. Otherwise please by all means
avoid this in general.

Thanks,
Willy

  parent reply	other threads:[~2019-09-20 17:26 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20190912034421.GA2085@darwi-home-pc>
     [not found] ` <20190912082530.GA27365@mit.edu>
     [not found]   ` <CAHk-=wjyH910+JRBdZf_Y9G54c1M=LBF8NKXB6vJcm9XjLnRfg@mail.gmail.com>
     [not found]     ` <20190914122500.GA1425@darwi-home-pc>
     [not found]       ` <008f17bc-102b-e762-a17c-e2766d48f515@gmail.com>
     [not found]         ` <20190915052242.GG19710@mit.edu>
     [not found]           ` <CAHk-=wgg2T=3KxrO-BY3nHJgMEyApjnO3cwbQb_0vxsn9qKN8Q@mail.gmail.com>
     [not found]             ` <20190918211503.GA1808@darwi-home-pc>
     [not found]               ` <20190918211713.GA2225@darwi-home-pc>
     [not found]                 ` <CAHk-=wiCqDiU7SE3FLn2W26MS_voUAuqj5XFa1V_tiGTrrW-zQ@mail.gmail.com>
2019-09-20 13:46                   ` [PATCH RFC v4 1/1] random: WARN on large getrandom() waits and introduce getrandom2() Ahmed S. Darwish
2019-09-20 14:33                     ` Andy Lutomirski
2019-09-20 16:29                       ` Linus Torvalds
2019-09-20 17:52                         ` Andy Lutomirski
2019-09-20 18:09                           ` Linus Torvalds
2019-09-20 18:16                             ` Willy Tarreau
2019-09-20 19:12                             ` Andy Lutomirski
2019-09-20 19:51                               ` Linus Torvalds
2019-09-20 20:11                                 ` Alexander E. Patrakov
2019-09-20 20:17                                 ` Matthew Garrett
2019-09-20 20:51                                 ` Andy Lutomirski
2019-09-20 22:44                                   ` Linus Torvalds
2019-09-20 23:30                                     ` Andy Lutomirski
2019-09-21  3:05                                       ` Willy Tarreau
2019-09-21  6:07                             ` Florian Weimer
2019-09-23 18:33                               ` Andy Lutomirski
2019-09-26 21:11                                 ` Ahmed S. Darwish
2019-09-20 18:12                           ` Willy Tarreau
2019-09-20 19:22                             ` Andy Lutomirski
2019-09-20 19:37                               ` Willy Tarreau
2019-09-20 19:52                                 ` Andy Lutomirski
2019-09-20 20:02                               ` Linus Torvalds
2019-09-20 18:15                           ` Alexander E. Patrakov
2019-09-20 18:29                             ` Andy Lutomirski
2019-09-20 17:26                     ` Willy Tarreau [this message]
2019-09-20 17:56                       ` Ahmed S. Darwish
2019-09-26 20:42                   ` [PATCH v5 0/1] random: getrandom(2): warn on large CRNG waits, introduce new flags Ahmed S. Darwish
2019-09-26 20:44                     ` [PATCH v5 1/1] " Ahmed S. Darwish
2019-09-26 21:39                       ` Andy Lutomirski
2019-09-28  9:30                         ` Ahmed S. Darwish

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=20190920172609.GA1832@1wt.eu \
    --to=w@1wt.eu \
    --cc=darwish.07@gmail.com \
    --cc=ebiederm@xmission.com \
    --cc=linux-api@vger.kernel.org \
    --cc=linux-ext4@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-man@vger.kernel.org \
    --cc=mjg59@srcf.ucam.org \
    --cc=mtk.manpages@gmail.com \
    --cc=mzxreary@0pointer.de \
    --cc=patrakov@gmail.com \
    --cc=torvalds@linux-foundation.org \
    --cc=tytso@mit.edu \
    /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).