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From: Lennart Poettering <mzxreary@0pointer.de>
To: "Alexander E. Patrakov" <patrakov@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
	Willy Tarreau <w@1wt.eu>, Matthew Garrett <mjg59@srcf.ucam.org>,
	"Ahmed S. Darwish" <darwish.07@gmail.com>,
	"Theodore Y. Ts'o" <tytso@mit.edu>,
	Vito Caputo <vcaputo@pengaru.com>,
	Andreas Dilger <adilger.kernel@dilger.ca>,
	Jan Kara <jack@suse.cz>, Ray Strode <rstrode@redhat.com>,
	William Jon McCann <mccann@jhu.edu>,
	zhangjs <zachary@baishancloud.com>,
	linux-ext4@vger.kernel.org, lkml <linux-kernel@vger.kernel.org>
Subject: Re: Linux 5.3-rc8
Date: Tue, 17 Sep 2019 19:30:36 +0200	[thread overview]
Message-ID: <20190917173036.GC31798@gardel-login> (raw)
In-Reply-To: <6ae36cda-5045-6873-9727-1d36bf45b84e@gmail.com>

On Di, 17.09.19 21:58, Alexander E. Patrakov (patrakov@gmail.com) wrote:

> I am worried that the getrandom delays will be serialized, because processes
> sometimes run one after another. If there are enough chained/dependent
> processes that ask for randomness before it is ready, the end result is
> still a too-big delay, essentially a failed boot.
>
> In other words: your approach of adding delays only makes sense for heavily
> parallelized boot, which may not be the case, especially for embedded
> systems that don't like systemd.

As mentioned elsewhere: once the pool is initialized it's
initialized. This means any pending getrandom() on the whole system
will unblock at the same time, and from the on all getrandom()s will
be non-blocking.

systemd-random-seed.service is nowadays a synchronization point for
exactly the moment where the pool is considered full.

Lennart

--
Lennart Poettering, Berlin

  reply	other threads:[~2019-09-17 17:30 UTC|newest]

Thread overview: 214+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-08 20:59 Linux 5.3-rc8 Linus Torvalds
2019-09-10  4:21 ` Ahmed S. Darwish
2019-09-10 11:33   ` Linus Torvalds
2019-09-10 12:21     ` Linus Torvalds
2019-09-10 17:33     ` Ahmed S. Darwish
2019-09-10 17:47       ` Reindl Harald
2019-09-10 18:21       ` Linus Torvalds
2019-09-11 16:07         ` Theodore Y. Ts'o
2019-09-11 16:45           ` Linus Torvalds
2019-09-11 17:00             ` Linus Torvalds
2019-09-11 17:36               ` Theodore Y. Ts'o
2019-09-12  3:44                 ` Ahmed S. Darwish
2019-09-12  8:25                   ` Theodore Y. Ts'o
2019-09-12 11:34                     ` Linus Torvalds
2019-09-12 11:58                       ` Willy Tarreau
2019-09-14 12:25                       ` [PATCH RFC] random: getrandom(2): don't block on non-initialized entropy pool Ahmed S. Darwish
2019-09-14 14:08                         ` Alexander E. Patrakov
2019-09-15  5:22                           ` [PATCH RFC v2] random: optionally block in getrandom(2) when the CRNG is uninitialized Theodore Y. Ts'o
2019-09-15  8:17                             ` [PATCH RFC v3] random: getrandom(2): optionally block when " Ahmed S. Darwish
2019-09-15  8:59                               ` Lennart Poettering
2019-09-15  9:30                                 ` Willy Tarreau
2019-09-15 10:02                                   ` Ahmed S. Darwish
2019-09-15 10:40                                     ` Willy Tarreau
2019-09-15 10:55                                       ` Ahmed S. Darwish
2019-09-15 11:17                                         ` Willy Tarreau
2019-09-15 17:32                             ` [PATCH RFC v2] random: optionally block in getrandom(2) when the " Linus Torvalds
2019-09-15 18:32                               ` Willy Tarreau
2019-09-15 18:36                                 ` Willy Tarreau
2019-09-15 19:08                                   ` Linus Torvalds
2019-09-15 19:18                                     ` Willy Tarreau
2019-09-15 19:31                                       ` Linus Torvalds
2019-09-15 19:54                                         ` Willy Tarreau
2019-09-15 18:59                                 ` Linus Torvalds
2019-09-15 19:12                                   ` Willy Tarreau
2019-09-16  2:45                                   ` Ahmed S. Darwish
2019-09-16 18:08                               ` Lennart Poettering
2019-09-16 19:16                                 ` Willy Tarreau
2019-09-18 21:15                               ` [PATCH RFC v4 0/1] random: WARN on large getrandom() waits and introduce getrandom2() Ahmed S. Darwish
2019-09-18 21:17                                 ` [PATCH RFC v4 1/1] " Ahmed S. Darwish
2019-09-18 23:57                                   ` Linus Torvalds
2019-09-19 14:34                                     ` Theodore Y. Ts'o
2019-09-19 15:20                                       ` Linus Torvalds
2019-09-19 15:50                                         ` Linus Torvalds
2019-09-20 13:13                                           ` Theodore Y. Ts'o
2019-09-19 20:04                                         ` Linus Torvalds
2019-09-19 20:45                                           ` Alexander E. Patrakov
2019-09-19 21:47                                             ` Linus Torvalds
2019-09-19 22:23                                               ` Alexander E. Patrakov
2019-09-19 23:44                                                 ` Alexander E. Patrakov
2019-09-20 13:16                                                 ` Theodore Y. Ts'o
2019-09-23 11:55                                           ` David Laight
2019-09-20 13:08                                         ` Theodore Y. Ts'o
2019-09-20 13:46                                     ` 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
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
2019-09-20  0:51                                   ` [random] ec47a799bf: WARNING:at_drivers/char/random.c:#getrandom_wait kernel test robot
2019-09-20  0:51                                     ` kernel test robot
2019-09-14 15:02                       ` Linux 5.3-rc8 Ahmed S. Darwish
2019-09-14 16:30                         ` Linus Torvalds
2019-09-14 16:35                           ` Alexander E. Patrakov
2019-09-14 16:52                             ` Linus Torvalds
2019-09-14 17:09                               ` Alexander E. Patrakov
2019-09-14 19:19                                 ` Linus Torvalds
2019-09-15  6:56                               ` Lennart Poettering
2019-09-15  7:01                                 ` Willy Tarreau
2019-09-15  7:05                                   ` Lennart Poettering
2019-09-15  7:07                                     ` Willy Tarreau
2019-09-15  8:34                                       ` Lennart Poettering
2019-09-15 17:02                                 ` Linus Torvalds
2019-09-16  3:23                                   ` Theodore Y. Ts'o
2019-09-16  3:40                                     ` Linus Torvalds
2019-09-16  3:56                                       ` Linus Torvalds
2019-09-16 17:00                                       ` Theodore Y. Ts'o
2019-09-16 17:07                                         ` Linus Torvalds
2019-09-14 21:11                           ` Ahmed S. Darwish
2019-09-14 22:05                             ` Martin Steigerwald
2019-09-14 22:24                             ` Theodore Y. Ts'o
2019-09-14 22:32                               ` Linus Torvalds
2019-09-15  1:00                                 ` Theodore Y. Ts'o
2019-09-15  1:10                                   ` Linus Torvalds
2019-09-15  2:05                                     ` Theodore Y. Ts'o
2019-09-15  2:11                                       ` Linus Torvalds
2019-09-15  6:33                                       ` Willy Tarreau
2019-09-15  6:53                                       ` Willy Tarreau
2019-09-15  6:51                           ` Lennart Poettering
2019-09-15  7:27                             ` Ahmed S. Darwish
2019-09-15  8:48                               ` Lennart Poettering
2019-09-15 16:29                             ` Linus Torvalds
2019-09-16  1:40                               ` Ahmed S. Darwish
2019-09-16  1:48                                 ` Vito Caputo
2019-09-16  2:49                                   ` Theodore Y. Ts'o
2019-09-16  4:29                                     ` Willy Tarreau
2019-09-16  5:02                                       ` Linus Torvalds
2019-09-16  6:12                                         ` Willy Tarreau
2019-09-16 16:17                                           ` Linus Torvalds
2019-09-16 17:21                                             ` Theodore Y. Ts'o
2019-09-16 17:44                                               ` Linus Torvalds
2019-09-16 17:55                                                 ` Serge Belyshev
2019-09-16 19:08                                                 ` Willy Tarreau
2019-09-16 23:02                                                 ` Matthew Garrett
2019-09-16 23:05                                                   ` Linus Torvalds
2019-09-16 23:11                                                     ` Matthew Garrett
2019-09-16 23:13                                                       ` Alexander E. Patrakov
2019-09-16 23:15                                                         ` Matthew Garrett
2019-09-16 23:18                                                       ` Linus Torvalds
2019-09-16 23:29                                                         ` Ahmed S. Darwish
2019-09-17  1:05                                                           ` Linus Torvalds
2019-09-17  1:23                                                             ` Matthew Garrett
2019-09-17  1:41                                                               ` Linus Torvalds
2019-09-17  1:46                                                                 ` Matthew Garrett
2019-09-17  5:24                                                                   ` Willy Tarreau
2019-09-17  7:33                                                                     ` Martin Steigerwald
2019-09-17  8:35                                                                       ` Willy Tarreau
2019-09-17  8:44                                                                         ` Martin Steigerwald
2019-09-17 12:11                                                                       ` Theodore Y. Ts'o
2019-09-17 12:30                                                                         ` Ahmed S. Darwish
2019-09-17 12:46                                                                           ` Alexander E. Patrakov
2019-09-17 12:47                                                                           ` Willy Tarreau
2019-09-17 16:08                                                                           ` Lennart Poettering
2019-09-17 16:23                                                                             ` Linus Torvalds
2019-09-17 16:34                                                                               ` Reindl Harald
2019-09-17 17:42                                                                               ` Lennart Poettering
2019-09-17 18:01                                                                                 ` Linus Torvalds
2019-09-17 20:28                                                                                   ` Martin Steigerwald
2019-09-17 20:52                                                                                     ` Ahmed S. Darwish
2019-09-17 21:38                                                                                       ` Martin Steigerwald
2019-09-17 21:52                                                                                         ` Matthew Garrett
2019-09-17 22:10                                                                                           ` Martin Steigerwald
2019-09-18 13:53                                                                                             ` Lennart Poettering
2019-09-19  7:28                                                                                               ` Martin Steigerwald
2019-09-17 23:08                                                                                           ` Linus Torvalds
2019-09-18 13:40                                                                                         ` Lennart Poettering
2019-09-17 20:58                                                                                   ` Linus Torvalds
2019-09-18  9:33                                                                                     ` Rasmus Villemoes
2019-09-18 10:16                                                                                       ` Willy Tarreau
2019-09-18 10:25                                                                                         ` Alexander E. Patrakov
2019-09-18 10:42                                                                                           ` Willy Tarreau
2019-09-18 19:31                                                                                       ` Linus Torvalds
2019-09-18 19:56                                                                                 ` Eric W. Biederman
2019-09-18 20:13                                                                                   ` Linus Torvalds
2019-09-18 20:15                                                                                   ` Alexander E. Patrakov
2019-09-18 20:26                                                                                     ` Linus Torvalds
2019-09-18 22:12                                                                                       ` Willy Tarreau
2019-09-27 13:57                                                                                       ` Lennart Poettering
2019-09-27 15:58                                                                                         ` Linus Torvalds
2019-09-29  9:05                                                                                           ` Lennart Poettering
2019-09-17 13:11                                                                         ` Alexander E. Patrakov
2019-09-17 13:37                                                                           ` Alexander E. Patrakov
2019-09-17 15:57                                                                         ` Lennart Poettering
2019-09-17 16:21                                                                           ` Willy Tarreau
2019-09-17 17:13                                                                             ` Lennart Poettering
2019-09-17 17:29                                                                               ` Willy Tarreau
2019-09-17 20:42                                                                                 ` Martin Steigerwald
2019-09-18 13:38                                                                                 ` Lennart Poettering
2019-09-18 13:59                                                                                   ` Alexander E. Patrakov
2019-09-18 14:50                                                                                     ` Alexander E. Patrakov
2019-09-17 20:36                                                                             ` Martin Steigerwald
2019-09-17 16:27                                                                       ` Linus Torvalds
2019-09-17 16:34                                                                         ` Matthew Garrett
2019-09-17 17:16                                                                           ` Willy Tarreau
2019-09-17 17:20                                                                             ` Matthew Garrett
2019-09-17 17:23                                                                               ` Matthew Garrett
2019-09-17 17:57                                                                               ` Willy Tarreau
2019-09-17 16:58                                                                         ` Alexander E. Patrakov
2019-09-17 17:30                                                                           ` Lennart Poettering [this message]
2019-09-17 17:32                                                                             ` Willy Tarreau
2019-09-17 17:41                                                                               ` Alexander E. Patrakov
2019-09-17 17:28                                                                         ` Lennart Poettering
2019-09-17  0:03                                                         ` Matthew Garrett
2019-09-17  0:40                                                         ` Matthew Garrett
2019-09-17  7:15                                                     ` a sane approach to random numbers (was: Re: Linux 5.3-rc8) Martin Steigerwald
2019-09-16 18:00                                               ` Linux 5.3-rc8 Alexander E. Patrakov
2019-09-16 19:53                                               ` Ahmed S. Darwish
2019-09-17 15:32                                               ` Lennart Poettering
2019-09-16  3:31                                 ` Linus Torvalds
2019-09-23 20:49                           ` chaos generating driver was " Pavel Machek
2019-09-14  9:25                     ` Ahmed S. Darwish
2019-09-14 16:27                       ` Theodore Y. Ts'o
2019-09-11 21:41             ` Ahmed S. Darwish
2019-09-11 22:37               ` Ahmed S. Darwish
2019-09-16  3:52           ` Herbert Xu
2019-09-16  4:21             ` Linus Torvalds
2019-09-16  4:53               ` Willy Tarreau
2019-09-10 11:56   ` Theodore Y. Ts'o
2019-09-16 10:33     ` Christoph Hellwig
2019-10-03 21:10   ` Jon Masters
2019-10-03 21:31   ` Jon Masters

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