linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Peter Zijlstra <peterz@infradead.org>
To: Alexey Dobriyan <adobriyan@gmail.com>
Cc: mingo@redhat.com, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2] sched: make nr_running() return "unsigned int"
Date: Thu, 12 Mar 2020 11:44:27 +0100	[thread overview]
Message-ID: <20200312104427.GR12561@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20200311210608.GA4517@avx2>

On Thu, Mar 12, 2020 at 12:06:08AM +0300, Alexey Dobriyan wrote:
> I don't anyone have been crazy enough to spawn 2^32 threads.
> It'd require absurd amounts of physical memory.

And we're going to 5 level page-tables because 48 bits physical isn't
enough. 57 bits of physical is plenty space to spawn that many tasks and
still have some left over.

Now 32 bit tasks is indeed insane, but memory isn't the problem. The
actual limit is the pid-space, which is 30 bits.

  parent reply	other threads:[~2020-03-12 10:44 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-11 21:06 Alexey Dobriyan
2020-03-11 21:08 ` [PATCH 2/2] sched: make nr_iowait_cpu() " Alexey Dobriyan
2020-03-12 10:44 ` Peter Zijlstra [this message]
2020-03-12 17:09   ` [PATCH 1/2] sched: make nr_running() " Alexey Dobriyan

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=20200312104427.GR12561@hirez.programming.kicks-ass.net \
    --to=peterz@infradead.org \
    --cc=adobriyan@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@redhat.com \
    --subject='Re: [PATCH 1/2] sched: make nr_running() return "unsigned int"' \
    /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

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).