From: Matthew Wilcox <willy@infradead.org>
To: Daniel Colascione <dancol@google.com>
Cc: Pavel Machek <pavel@ucw.cz>, Vlastimil Babka <vbabka@suse.cz>,
linux-kernel <linux-kernel@vger.kernel.org>,
Mike Rapoport <rppt@linux.ibm.com>,
Tim Murray <timmurray@google.com>,
Joel Fernandes <joelaf@google.com>,
Suren Baghdasaryan <surenb@google.com>,
Jonathan Corbet <corbet@lwn.net>,
Andrew Morton <akpm@linux-foundation.org>,
Roman Gushchin <guro@fb.com>,
Mike Rapoport <rppt@linux.vnet.ibm.com>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
"Dennis Zhou (Facebook)" <dennisszhou@gmail.com>,
Prashant Dhamdhere <pdhamdhe@redhat.com>,
"open list:DOCUMENTATION" <linux-doc@vger.kernel.org>
Subject: Re: [PATCH v2] Document /proc/pid PID reuse behavior
Date: Tue, 20 Nov 2018 09:59:47 -0800 [thread overview]
Message-ID: <20181120175947.GE3065@bombadil.infradead.org> (raw)
In-Reply-To: <CAKOZuevidVnZ+9vB1CxsetPVH=2P7eoORA1F445HOp-jS5rwOA@mail.gmail.com>
On Tue, Nov 20, 2018 at 09:48:27AM -0800, Daniel Colascione wrote:
> On Tue, Nov 20, 2018 at 9:39 AM Matthew Wilcox <willy@infradead.org> wrote:
> > We have a limit on the number of FDs a process can have open for a reason.
> > Well, for many reasons.
>
> And the typical limit is too low. (I've seen people clamp it to 1024
> for some reason.)
1024 is the soft limit. 4096 is the default hard limit. You can always
ask root to set your hard limit higher if that's what you need.
> A file descriptor is just a handle to a kernel
> resource. All kernel resources held on behalf of applications need
> *some* kind of management interface. File descriptors provide a
> consistent and uniform instance of such a management interface. Unless
> there's a very good reason, nobody should be using non-FD handles for
> kernel resource management. A low default FD table size limit is not
> an example of one of these good reasons, not when we can raise FD
> table size limit. In general, the software projects should not have to
> put up with ugly workarounds for limitations they impose on
> themselves.
I'm not really sure why you decided to go off on this rant. My point to
Pavel was that there's no way a single process can tie up all of the PIDs.
Unless root decided to let them shoot everybody else in the system in
the foot.
next prev parent reply other threads:[~2018-11-20 18:00 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-31 15:06 [PATCH] Document /proc/pid PID reuse behavior Daniel Colascione
2018-11-01 7:08 ` Mike Rapoport
2018-11-05 13:22 ` [PATCH v2] " Daniel Colascione
2018-11-06 6:01 ` Mike Rapoport
2018-11-07 17:16 ` Matthew Wilcox
2018-11-07 18:21 ` Daniel Colascione
2018-11-06 13:05 ` Michal Hocko
2018-11-07 15:48 ` Daniel Colascione
2018-11-07 16:00 ` Michal Hocko
2018-11-07 16:10 ` Daniel Colascione
2018-11-07 16:19 ` Michal Hocko
2018-11-19 11:16 ` Aleksa Sarai
2018-11-07 17:04 ` Martin Steigerwald
2018-11-08 12:02 ` David Laight
2018-11-08 12:27 ` Matthew Wilcox
2018-11-08 13:42 ` David Laight
2018-11-08 14:07 ` Matthew Wilcox
2018-11-08 14:14 ` David Laight
2018-11-08 13:25 ` Michal Hocko
2018-11-19 10:54 ` Pavel Machek
2018-11-19 16:24 ` Daniel Colascione
2018-11-20 8:50 ` Pavel Machek
2018-11-20 9:05 ` Vlastimil Babka
2018-11-20 9:18 ` Pavel Machek
2018-11-20 17:39 ` Matthew Wilcox
2018-11-20 17:48 ` Daniel Colascione
2018-11-20 17:59 ` Matthew Wilcox [this message]
2018-11-20 16:37 ` Joel Fernandes
2018-11-20 16:49 ` Jonathan Corbet
2018-11-20 16:57 ` Pavel Machek
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