Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754646AbdIGKIM (ORCPT ); Thu, 7 Sep 2017 06:08:12 -0400 Received: from vmicros1.altlinux.org ([194.107.17.57]:49452 "EHLO vmicros1.altlinux.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753927AbdIGKIL (ORCPT ); Thu, 7 Sep 2017 06:08:11 -0400 Date: Thu, 7 Sep 2017 13:08:09 +0300 From: "Dmitry V. Levin" To: Alexey Dobriyan Cc: akpm@linux-foundation.org, Tatsiana Brouka , linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, Aliaksandr Patseyenak , Andrey Vagin Subject: Re: [PATCH 1/2] pidmap(2) Message-ID: <20170907100809.GD27490@altlinux.org> Mail-Followup-To: Alexey Dobriyan , akpm@linux-foundation.org, Tatsiana Brouka , linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, Aliaksandr Patseyenak , Andrey Vagin References: <20170905190500.GA13746@avx2> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="hxkXGo8AKqTJ+9QI" Content-Disposition: inline In-Reply-To: <20170905190500.GA13746@avx2> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1794 Lines: 50 --hxkXGo8AKqTJ+9QI Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Sep 05, 2017 at 10:05:00PM +0300, Alexey Dobriyan wrote: > From: Tatsiana Brouka >=20 > Implement system call for bulk retrieveing of pids in binary form. >=20 > Using /proc is slower than necessary: 3 syscalls + another 3 for each thr= ead + > converting with atoi(). >=20 > /proc may be not mounted especially in containers. Natural extension of > hidepid=3D2 efforts is to not mount /proc at all. >=20 > It could be used by programs like ps, top or CRIU. Speed increase will > become more drastic once combined with bulk retrieval of process statisti= cs. What could give a noticeable performance gain in a less ridiculous way is an interface like task_diag, see https://lkml.org/lkml/2016/4/11/924 . --=20 ldv --hxkXGo8AKqTJ+9QI Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIcBAEBCAAGBQJZsRqIAAoJEAVFT+BVnCUIrU8P/R2+YZN7dlUVpp+JQGFe4hng 0LYozC83phSxXRZJGTPLsOU4+XWk+dwXf2PHVLT2jdxv+iSsGK+TYu8wrb0jqqhl zwnzz99bnsCVv9pt4E3nheI9TXaMP6XKWyxAADbNbjIT9P+MfjL1ZuKg/UNZa1Wx 2HTpnyPEkw/4fOTWBLYeE45xNq1nJ0PK0tfJd5HQ/re8fHFfgGYr+UPIbt6V9gtV 10x7YCVY8qGouBwpMhuQNtfIp0RmmVNl58usoEUHlU7xLNNBaRKQVDFzQJHrGJho b9aGxFVSrZDMkSYqrPfk3g0wFbEFI4O4djJVquNXK30lF5DH/MSa0LKBweREDfGw mFSJkKTqYKsc3lL7aJsK/d5PCyK40RsCg0SUAyeE95RKcsBczpcpWuJlxJckZMc4 AfmKJncayayq9KGcMkvsLuxPE3sXtO4UXhumeSED4q2jryJjTxEfOTVTjEXUd6jC A0X0z6qD1mO4NBQY2glN1wRT5Xa34QwSvzep/PsXcsN0PuXZO+e/qADO55MZwPlt mz4DOOGXosHbWtPYAr5NffLidBVjgACfdKKW/rHEsADi3fps0B6J4w/POlCx0CpV wWL6AvbKhEzivx4WpVquNfr+QaUFSXyZY/Yeof0CjIjTMbPNMazO55C8QJ5AvwjZ NbcmI3TPLeIrVtcsL79f =vrgx -----END PGP SIGNATURE----- --hxkXGo8AKqTJ+9QI--