From: Cyrill Gorcunov <gorcunov@gmail.com>
To: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Dmitry Safonov <dima@arista.com>,
linux-kernel@vger.kernel.org,
Dmitry Safonov <0x7f454c46@gmail.com>,
Andrei Vagin <avagin@openvz.org>, Adrian Reber <adrian@lisas.de>,
Andy Lutomirski <luto@kernel.org>,
Christian Brauner <christian.brauner@ubuntu.com>,
"Eric W. Biederman" <ebiederm@xmission.com>,
"H. Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@redhat.com>,
Jeff Dike <jdike@addtoit.com>, Oleg Nesterov <oleg@redhat.com>,
Pavel Emelyanov <xemul@virtuozzo.com>,
Shuah Khan <shuah@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
containers@lists.linux-foundation.org, criu@openvz.org,
linux-api@vger.kernel.org, x86@kernel.org
Subject: Re: [RFC 02/20] timens: Add timens_offsets
Date: Fri, 21 Sep 2018 01:14:48 +0300 [thread overview]
Message-ID: <20180920221448.GE20786@uranus> (raw)
In-Reply-To: <20180920184510.GC20786@uranus>
On Thu, Sep 20, 2018 at 09:45:10PM +0300, Cyrill Gorcunov wrote:
> On Wed, Sep 19, 2018 at 09:50:19PM +0100, Dmitry Safonov wrote:
> > From: Andrei Vagin <avagin@openvz.org>
> >
> > Introduce offsets for time namespace. They will contain adjustment
> > needed to convert clocks to/from host's.
> >
> > Allocate one page for each time namespace that will be premapped into
> > userspace with vvar pages.
>
> Is not it too much?! The whole page per each clone(new-time-ns) call.
> Moreover everytime it is get explicitly zeroifyed. Don't get me wrong,
> maybe I miss something obvious, but additional 4K per process, guys :)
After being talking to Andrew I think there is no better option though.
If syscalls would be free of course we could use them instead but this
vdso stuff, sigh. I thouhgh about modifying vdso code so it would carry
refs inside (or adding some section into elf loader kernel code), but
all this would simply mess the code. Thus this 4K per namespace seems
to be acceptable trade off.
next prev parent reply other threads:[~2018-09-20 22:14 UTC|newest]
Thread overview: 164+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-19 20:50 [RFC 00/20] ns: Introduce Time Namespace Dmitry Safonov
2018-09-19 20:50 ` Dmitry Safonov
2018-09-19 20:50 ` Dmitry Safonov
2018-09-19 20:50 ` dima
2018-09-19 20:50 ` [RFC 01/20] " Dmitry Safonov
2018-09-28 18:20 ` Laurent Vivier
2018-09-19 20:50 ` [RFC 02/20] timens: Add timens_offsets Dmitry Safonov
2018-09-20 18:45 ` Cyrill Gorcunov
2018-09-20 22:14 ` Cyrill Gorcunov [this message]
2018-09-19 20:50 ` [RFC 03/20] timens: Introduce CLOCK_MONOTONIC offsets Dmitry Safonov
2018-09-19 20:50 ` [RFC 04/20] timens: Introduce CLOCK_BOOTTIME offset Dmitry Safonov
2018-09-30 3:18 ` [LKP] [timens] 3cc8de9dcb: RIP:posix_get_boottime kernel test robot
2018-09-30 3:18 ` kernel test robot
2018-09-30 3:18 ` [LKP] " kernel test robot
2018-09-19 20:50 ` [RFC 05/20] timerfd/timens: Take into account ns clock offsets Dmitry Safonov
2018-09-19 20:50 ` [RFC 06/20] kernel: Take into account timens clock offsets in clock_nanosleep Dmitry Safonov
2018-09-19 20:50 ` [RFC 07/20] timens: Shift /proc/uptime Dmitry Safonov
2018-09-19 20:50 ` [RFC 08/20] x86/vdso: Restrict splitting vvar vma Dmitry Safonov
2018-09-19 20:50 ` [RFC 09/20] x86/vdso/timens: Add offsets page in vvar Dmitry Safonov
2018-09-19 20:50 ` [RFC 10/20] x86/vdso: Use set_normalized_timespec() to avoid 32 bit overflow Dmitry Safonov
2018-09-19 20:50 ` [RFC 11/20] x86/vdso: Purge timens page on setns()/unshare()/clone() Dmitry Safonov
2018-09-19 20:50 ` [RFC 12/20] x86/vdso: Look for vvar vma to purge timens page Dmitry Safonov
2018-09-19 20:50 ` [RFC 13/20] posix-timers/timens: Take into account clock offsets Dmitry Safonov
2018-09-30 3:11 ` [LKP] [posix] 25217c6e39: BUG:KASAN:null-ptr-deref_in_c kernel test robot
2018-09-30 3:11 ` kernel test robot
2018-09-30 3:11 ` [LKP] " kernel test robot
2018-09-19 20:50 ` [RFC 14/20] timens: Add align for timens_offsets Dmitry Safonov
2018-09-19 20:50 ` [RFC 15/20] timens: Optimize zero-offsets Dmitry Safonov
2018-09-19 20:50 ` [RFC 16/20] selftest: Add Time Namespace test for supported clocks Dmitry Safonov
2018-09-19 20:50 ` Dmitry Safonov
2018-09-19 20:50 ` dima
2018-09-24 21:36 ` Shuah Khan
2018-09-24 21:36 ` Shuah Khan
2018-09-24 21:36 ` shuah
2018-09-19 20:50 ` [RFC 17/20] selftest/timens: Add test for timerfd Dmitry Safonov
2018-09-19 20:50 ` Dmitry Safonov
2018-09-19 20:50 ` dima
2018-09-19 20:50 ` [RFC 18/20] selftest/timens: Add test for clock_nanosleep Dmitry Safonov
2018-09-19 20:50 ` Dmitry Safonov
2018-09-19 20:50 ` dima
2018-09-19 20:50 ` [RFC 19/20] timens/selftest: Add procfs selftest Dmitry Safonov
2018-09-19 20:50 ` Dmitry Safonov
2018-09-19 20:50 ` dima
2018-09-19 20:50 ` [RFC 20/20] timens/selftest: Add timer offsets test Dmitry Safonov
2018-09-19 20:50 ` Dmitry Safonov
2018-09-19 20:50 ` dima
2018-09-21 12:27 ` [RFC 00/20] ns: Introduce Time Namespace Eric W. Biederman
2018-09-21 12:27 ` Eric W. Biederman
2018-09-21 12:27 ` ebiederm
2018-09-24 20:51 ` Andrey Vagin
2018-09-24 20:51 ` Andrey Vagin
2018-09-24 20:51 ` Andrey Vagin
2018-09-24 20:51 ` avagin
2018-09-24 22:02 ` Eric W. Biederman
2018-09-24 22:02 ` Eric W. Biederman
2018-09-24 22:02 ` Eric W. Biederman
2018-09-24 22:02 ` ebiederm
2018-09-25 1:42 ` Andrey Vagin
2018-09-25 1:42 ` Andrey Vagin
2018-09-25 1:42 ` Andrey Vagin
2018-09-25 1:42 ` avagin
2018-09-26 17:36 ` Eric W. Biederman
2018-09-26 17:36 ` Eric W. Biederman
2018-09-26 17:36 ` Eric W. Biederman
2018-09-26 17:36 ` ebiederm
2018-09-26 17:59 ` Dmitry Safonov
2018-09-26 17:59 ` Dmitry Safonov
2018-09-26 17:59 ` Dmitry Safonov
2018-09-26 17:59 ` 0x7f454c46
2018-09-27 21:30 ` Thomas Gleixner
2018-09-27 21:30 ` Thomas Gleixner
2018-09-27 21:30 ` Thomas Gleixner
2018-09-27 21:30 ` tglx
2018-09-27 21:41 ` Thomas Gleixner
2018-09-27 21:41 ` Thomas Gleixner
2018-09-27 21:41 ` Thomas Gleixner
2018-09-27 21:41 ` tglx
2018-10-01 23:20 ` Andrey Vagin
2018-10-01 23:20 ` Andrey Vagin
2018-10-01 23:20 ` Andrey Vagin
2018-10-01 23:20 ` avagin
2018-10-02 6:15 ` Thomas Gleixner
2018-10-02 6:15 ` Thomas Gleixner
2018-10-02 6:15 ` Thomas Gleixner
2018-10-02 6:15 ` tglx
2018-10-02 21:05 ` Dmitry Safonov
2018-10-02 21:05 ` Dmitry Safonov
2018-10-02 21:05 ` 0x7f454c46
2018-10-02 21:26 ` Thomas Gleixner
2018-10-02 21:26 ` Thomas Gleixner
2018-10-02 21:26 ` tglx
2018-09-28 17:03 ` Eric W. Biederman
2018-09-28 17:03 ` Eric W. Biederman
2018-09-28 17:03 ` Eric W. Biederman
2018-09-28 17:03 ` ebiederm
2018-09-28 19:32 ` Thomas Gleixner
2018-09-28 19:32 ` Thomas Gleixner
2018-09-28 19:32 ` Thomas Gleixner
2018-09-28 19:32 ` tglx
2018-10-01 9:05 ` Eric W. Biederman
2018-10-01 9:05 ` Eric W. Biederman
2018-10-01 9:05 ` Eric W. Biederman
2018-10-01 9:05 ` ebiederm
2018-10-01 9:15 ` Setting monotonic time? Eric W. Biederman
2018-10-01 9:15 ` Eric W. Biederman
2018-10-01 9:15 ` Eric W. Biederman
2018-10-01 9:15 ` ebiederm
2018-10-01 18:52 ` Thomas Gleixner
2018-10-01 18:52 ` Thomas Gleixner
2018-10-01 18:52 ` Thomas Gleixner
2018-10-01 18:52 ` tglx
2018-10-02 20:00 ` Arnd Bergmann
2018-10-02 20:00 ` Arnd Bergmann
2018-10-02 20:00 ` arnd
2018-10-02 20:06 ` Thomas Gleixner
2018-10-02 20:06 ` Thomas Gleixner
2018-10-02 20:06 ` tglx
2018-10-03 4:50 ` Eric W. Biederman
2018-10-03 4:50 ` Eric W. Biederman
2018-10-03 4:50 ` ebiederm
2018-10-03 5:25 ` Thomas Gleixner
2018-10-03 5:25 ` Thomas Gleixner
2018-10-03 5:25 ` tglx
2018-10-03 6:14 ` Eric W. Biederman
2018-10-03 6:14 ` Eric W. Biederman
2018-10-03 6:14 ` ebiederm
2018-10-03 7:02 ` Arnd Bergmann
2018-10-03 7:02 ` Arnd Bergmann
2018-10-03 7:02 ` arnd
2018-10-03 6:14 ` Thomas Gleixner
2018-10-03 6:14 ` Thomas Gleixner
2018-10-03 6:14 ` tglx
2018-10-01 20:51 ` Andrey Vagin
2018-10-01 20:51 ` Andrey Vagin
2018-10-01 20:51 ` Andrey Vagin
2018-10-01 20:51 ` avagin
2018-10-02 6:16 ` Thomas Gleixner
2018-10-02 6:16 ` Thomas Gleixner
2018-10-02 6:16 ` Thomas Gleixner
2018-10-02 6:16 ` tglx
2018-10-21 1:41 ` [RFC 00/20] ns: Introduce Time Namespace Andrei Vagin
2018-10-21 1:41 ` Andrei Vagin
2018-10-21 1:41 ` Andrei Vagin
2018-10-21 1:41 ` avagin
2018-10-21 3:54 ` Andrei Vagin
2018-10-21 3:54 ` Andrei Vagin
2018-10-21 3:54 ` Andrei Vagin
2018-10-21 3:54 ` avagin
2018-10-29 20:33 ` Thomas Gleixner
2018-10-29 20:33 ` Thomas Gleixner
2018-10-29 20:33 ` Thomas Gleixner
2018-10-29 20:33 ` tglx
2018-10-29 21:21 ` Eric W. Biederman
2018-10-29 21:21 ` Eric W. Biederman
2018-10-29 21:21 ` Eric W. Biederman
2018-10-29 21:21 ` ebiederm
2018-10-29 21:36 ` Thomas Gleixner
2018-10-29 21:36 ` Thomas Gleixner
2018-10-29 21:36 ` Thomas Gleixner
2018-10-29 21:36 ` tglx
2018-10-31 16:26 ` Andrei Vagin
2018-10-31 16:26 ` Andrei Vagin
2018-10-31 16:26 ` Andrei Vagin
2018-10-31 16:26 ` avagin
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