unofficial mirror of libc-alpha@sourceware.org
 help / color / mirror / Atom feed
From: Arnd Bergmann <arnd@arndb.de>
To: Rich Felker <dalias@libc.org>
Cc: Alistair Francis <alistair23@gmail.com>,
	Christian Brauner <christian@brauner.io>,
	 "Eric W. Biederman" <ebiederm@xmission.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	 Alistair Francis <alistair.francis@wdc.com>,
	GNU C Library <libc-alpha@sourceware.org>,
	 Adhemerval Zanella <adhemerval.zanella@linaro.org>,
	Florian Weimer <fweimer@redhat.com>,
	 Palmer Dabbelt <palmer@sifive.com>,
	macro@wdc.com, Zong Li <zongbox@gmail.com>,
	 Andrew Morton <akpm@linux-foundation.org>,
	Al Viro <viro@zeniv.linux.org.uk>,
	 "H. Peter Anvin" <hpa@zytor.com>
Subject: Re: [RFC v3 03/23] sysdeps/wait: Use waitid if avaliable
Date: Thu, 25 Jul 2019 15:15:35 +0200	[thread overview]
Message-ID: <CAK8P3a1pjB8SMFQK0MUom0m5fCSAdVZFtJyeUkCLW-u-RHC3oA@mail.gmail.com> (raw)
In-Reply-To: <20190725044009.GJ1506@brightrain.aerifal.cx>

On Thu, Jul 25, 2019 at 6:40 AM Rich Felker <dalias@libc.org> wrote:
> On Wed, Jul 24, 2019 at 05:04:53PM -0700, Alistair Francis wrote:
> > On Tue, Jul 23, 2019 at 1:45 AM Arnd Bergmann <arnd@arndb.de> wrote:
> > >
> > > Sounds good to me, the debate over what rusage to use should not hold
> > > up the review of the rest of that syscall.
> >
> > I'm unclear what the final decision is here. What is the solution are
> > we going to have wait4() or add P_PROCESS_PGID to waitid()?
> >
> > As well as that what is the solution to current implementations? If we
> > add wait4() then there isn't an issue (and I can drop this patch) but
> > if we add P_PROCESS_PGID then we will need a way to handle kernels
> > with waitid() but no P_PROCESS_PGID. Although my new plan is to only
> > use the waitid syscall if we don't have waitpid or wait4 so it seems
> > like this will only affect RV32 for the time being.
>
> I would really like some indication which solution will be taken,
> since it impacts choices that will need to be made in musl very soon.
> My favorite outcome would be bringing back wait4 for rv32 (and
> no-time32 archs in general) *and* adding P_PROCESS_PGID. In the short
> term, just using wait4 would be the simplest and cleanest for us (same
> as all other archs, no extra case to deal with), but in the long term
> there may be value in having rusage that can represent more than 68
> cpu-years spent by a process (seems plausible with large numbers of
> cores).

Based on the feedback from Linus and Eric, the most likely outcome
at the moment seems to be an extension of waitid() to allow
P_PGID with id=0 like BSD does, and not bring back wait4() or
add P_PROCESS_PGID.

So far, I don't think anyone has proposed an actual kernel patch.
I was hoping that Eric would do it, but I could also send it if he's
otherwise busy.

      Arnd

  reply	other threads:[~2019-07-25 13:23 UTC|newest]

Thread overview: 127+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-17  0:08 [RFC v3 00/23] RISC-V glibc port for the 32-bit Alistair Francis
2019-07-17  0:08 ` [RFC v3 01/23] sysdeps/nanosleep: Use clock_nanosleep_time64 if avaliable Alistair Francis
2019-07-17  5:16   ` Florian Weimer
2019-07-19 17:25     ` Alistair Francis
2019-07-20 14:24       ` Stepan Golosunov
2019-07-22 21:14         ` Alistair Francis
2019-07-17  0:08 ` [RFC v3 02/23] sysdeps/gettimeofday: Use clock_gettime64 " Alistair Francis
2019-07-17  7:09   ` Florian Weimer
2019-07-20  3:20     ` Rich Felker
2019-07-25 20:54       ` Joseph Myers
2019-07-17 12:43   ` Lukasz Majewski
2019-07-17 12:48     ` Lukasz Majewski
2019-07-19 22:26     ` Alistair Francis
2019-07-17  0:08 ` [RFC v3 03/23] sysdeps/wait: Use waitid " Alistair Francis
2019-07-17  5:31   ` Florian Weimer
2019-07-19 17:49     ` Alistair Francis
2019-07-22 15:58       ` Florian Weimer
2019-07-22 21:02         ` Alistair Francis
2019-07-21  4:03   ` Rich Felker
2019-07-21  4:20     ` Rich Felker
2019-07-21 11:59       ` Eric W. Biederman
2019-07-21 22:59         ` Rich Felker
2019-07-21  7:57     ` Arnd Bergmann
2019-07-21 12:15       ` Eric W. Biederman
2019-07-21 12:28         ` Christian Brauner
2019-07-21 14:30         ` Arnd Bergmann
2019-07-21 15:45           ` Eric W. Biederman
2019-07-21 17:05             ` Arnd Bergmann
2019-07-21 17:16             ` Linus Torvalds
2019-07-21 21:40               ` Eric W. Biederman
2019-07-21 23:23                 ` Rich Felker
2019-07-23  0:00                   ` Eric W. Biederman
2019-07-23  8:12                     ` Arnd Bergmann
2019-07-23  8:28                       ` Christian Brauner
2019-07-23  8:45                         ` Arnd Bergmann
2019-07-25  0:04                           ` Alistair Francis
2019-07-25  4:40                             ` Rich Felker
2019-07-25 13:15                               ` Arnd Bergmann [this message]
2019-07-25 16:06                                 ` Christian Brauner
2019-07-25 17:14                                 ` Eric W. Biederman
2019-07-25 17:30                                   ` Christian Brauner
2019-08-13 22:22                                     ` Alistair Francis
2019-08-13 23:11                                       ` Rich Felker
2019-08-14  5:07                                         ` Christian Brauner
2019-08-14 11:38                                       ` [PATCH v1 0/1] waitid: process group enhancement christian.brauner
2019-08-14 11:38                                         ` [PATCH v1 1/1] waitid: Add support for waiting for the current process group christian.brauner
2019-08-14 12:29                                           ` Oleg Nesterov
2019-08-14 12:45                                             ` Christian Brauner
2019-08-14 12:50                                               ` Oleg Nesterov
2019-08-14 12:53                                                 ` Christian Brauner
2019-08-14 13:07                                       ` [PATCH v2 0/1] waitid: process group enhancement Christian Brauner
2019-08-14 13:07                                         ` [PATCH v2 1/1] waitid: Add support for waiting for the current process group Christian Brauner
2019-08-14 14:19                                           ` Oleg Nesterov
2019-08-14 14:35                                             ` Christian Brauner
2019-08-14 15:27                                               ` Oleg Nesterov
2019-08-14 15:30                                                 ` Christian Brauner
2019-08-14 15:43                                       ` [PATCH v3 0/1] waitid: process group enhancement Christian Brauner
2019-08-14 15:44                                         ` [PATCH v3 1/1] waitid: Add support for waiting for the current process group Christian Brauner
2019-08-14 16:09                                           ` Oleg Nesterov
2019-08-14 16:15                                             ` Christian Brauner
2019-08-14 16:34                                               ` Christian Brauner
2019-08-14 16:55                                                 ` Rich Felker
2019-08-14 17:02                                                   ` Christian Brauner
2019-08-14 17:06                                                   ` Linus Torvalds
2019-08-14 18:00                                                     ` Rich Felker
2019-08-14 20:50                                             ` Christian Brauner
2019-08-14 15:58                                         ` [PATCH v3 0/1] waitid: process group enhancement Rich Felker
2019-08-14 16:13                                           ` Christian Brauner
2019-07-26 23:35                                   ` [RFC v3 03/23] sysdeps/wait: Use waitid if avaliable Alistair Francis
2019-07-17  0:08 ` [RFC v3 04/23] sysdeps/clock_gettime: Use clock_gettime64 " Alistair Francis
2019-07-17  5:38   ` Florian Weimer
2019-07-17  8:04     ` Arnd Bergmann
2019-07-17  8:44       ` Florian Weimer
2019-07-17  9:10         ` Arnd Bergmann
2019-07-17 15:16           ` Florian Weimer
2019-07-18  7:38             ` Arnd Bergmann
2019-07-18  8:18               ` Florian Weimer
2019-07-18  9:14                 ` Arnd Bergmann
2019-07-18 18:10                 ` Adhemerval Zanella
2019-07-19 21:03     ` Alistair Francis
2019-07-17  7:03   ` Andreas Schwab
2019-07-17 12:37   ` Lukasz Majewski
2019-07-17  0:08 ` [RFC v3 05/23] sysdeps/timespec_get: " Alistair Francis
2019-07-17  5:08   ` Florian Weimer
2019-07-17  7:59     ` Arnd Bergmann
2019-07-17  8:11       ` Florian Weimer
2019-07-17  8:23         ` Arnd Bergmann
2019-07-17  8:41           ` Florian Weimer
2019-07-17  8:54             ` Arnd Bergmann
2019-07-25 20:14       ` Joseph Myers
2019-07-17 12:22   ` Lukasz Majewski
2019-07-17  0:08 ` [RFC v3 06/23] Documentation for the RISC-V 32-bit port Alistair Francis
2019-07-17  0:08 ` [RFC v3 07/23] RISC-V: Use 64-bit time_t and off_t for RV32 and RV64 Alistair Francis
2019-07-17  8:27   ` Arnd Bergmann
2019-07-17 22:39     ` Alistair Francis
2019-07-18  7:41       ` Arnd Bergmann
2019-07-18 17:36         ` Alistair Francis
2019-07-19  6:44           ` Arnd Bergmann
2019-07-19 17:02             ` Alistair Francis
2019-07-17  0:09 ` [RFC v3 08/23] RISC-V: define __NR_futex as __NR_futex_time64 for 32-bit Alistair Francis
2019-07-17  0:09 ` [RFC v3 09/23] RISC-V: define __NR_* as __NR_*_time64/64 " Alistair Francis
2019-07-17  0:09 ` [RFC v3 10/23] RISC-V: define __NR_clock_getres as __NR_*_time64 " Alistair Francis
2019-07-17  0:09 ` [RFC v3 11/23] RISC-V: define __vdso_clock_getres as __vdso_clock_getres_time64 " Alistair Francis
2019-07-17  0:09 ` [RFC v3 12/23] RISC-V: define __vdso_clock_gettime as __vdso_clock_gettime64 " Alistair Francis
2019-07-17  8:16   ` Arnd Bergmann
2019-07-19 17:15     ` Alistair Francis
2019-07-17  0:09 ` [RFC v3 13/23] RISC-V: Use 64-bit timespec in clock_gettime vdso calls Alistair Francis
2019-07-17  8:13   ` Arnd Bergmann
2019-07-17  0:09 ` [RFC v3 14/23] RISC-V: Support dynamic loader for the 32-bit Alistair Francis
2019-07-17  0:09 ` [RFC v3 15/23] RISC-V: Add path of library directories " Alistair Francis
2019-07-17 12:20   ` Florian Weimer
2019-07-17  0:09 ` [RFC v3 16/23] RISC-V: The ABI implementation " Alistair Francis
2019-07-17  0:09 ` [RFC v3 17/23] RISC-V: Hard float support for the 32 bit Alistair Francis
2019-07-17  0:09 ` [RFC v3 18/23] RISC-V: Regenerate ULPs of RISC-V Alistair Francis
2019-07-17  0:09 ` [RFC v3 19/23] RISC-V: Add ABI lists Alistair Francis
2019-07-17  0:09 ` [RFC v3 20/23] RISC-V: Build Infastructure for the 32-bit Alistair Francis
2019-07-17  0:09 ` [RFC v3 21/23] RISC-V: Fix llrint and llround missing exceptions on RV32 Alistair Francis
2019-07-17 12:22   ` Florian Weimer
2019-07-17 22:32     ` Alistair Francis
2019-07-17  0:09 ` [RFC v3 22/23] Add RISC-V 32-bit target to build-many-glibcs.py Alistair Francis
2019-07-17  0:09 ` [RFC v3 23/23] RISC-V: Use 64-bit vdso syscalls Alistair Francis
2019-07-17  5:33   ` Florian Weimer
2019-07-17  8:02     ` Arnd Bergmann
2019-07-17 22:23       ` Alistair Francis
2019-07-17 23:42         ` Alistair Francis
2019-07-18  0:01           ` Alistair Francis
2019-07-19 17:14 ` [RFC v3 00/23] RISC-V glibc port for the 32-bit Alistair Francis

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

  List information: https://www.gnu.org/software/libc/involved.html

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=CAK8P3a1pjB8SMFQK0MUom0m5fCSAdVZFtJyeUkCLW-u-RHC3oA@mail.gmail.com \
    --to=arnd@arndb.de \
    --cc=adhemerval.zanella@linaro.org \
    --cc=akpm@linux-foundation.org \
    --cc=alistair.francis@wdc.com \
    --cc=alistair23@gmail.com \
    --cc=christian@brauner.io \
    --cc=dalias@libc.org \
    --cc=ebiederm@xmission.com \
    --cc=fweimer@redhat.com \
    --cc=hpa@zytor.com \
    --cc=libc-alpha@sourceware.org \
    --cc=macro@wdc.com \
    --cc=palmer@sifive.com \
    --cc=torvalds@linux-foundation.org \
    --cc=viro@zeniv.linux.org.uk \
    --cc=zongbox@gmail.com \
    /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 read-only IMAP folder(s) and NNTP newsgroup(s).