From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932559AbdKOVMD (ORCPT ); Wed, 15 Nov 2017 16:12:03 -0500 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:45548 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753780AbdKOVLy (ORCPT ); Wed, 15 Nov 2017 16:11:54 -0500 Date: Wed, 15 Nov 2017 22:11:52 +0100 From: Pavel Machek To: Shawn Landden Cc: kernel list Subject: Re: [RFC v2] prctl: prctl(PR_SET_IDLE, PR_IDLE_MODE_KILLME), for stateless idle loops Message-ID: <20171115211152.GA6183@amd> References: <20171101053244.5218-1-slandden@gmail.com> <20171103063544.13383-1-slandden@gmail.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="ikeVEW9yuYc//A+q" Content-Disposition: inline In-Reply-To: <20171103063544.13383-1-slandden@gmail.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --ikeVEW9yuYc//A+q Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi! > It is common for services to be stateless around their main event loop. > If a process sets PR_SET_IDLE to PR_IDLE_MODE_KILLME then it > signals to the kernel that epoll_wait() and friends may not complete, > and the kernel may send SIGKILL if resources get tight. >=20 > See my systemd patch: https://github.com/shawnl/systemd/tree/prctl >=20 > Android uses this memory model for all programs, and having it in the > kernel will enable integration with the page cache (not in this > series). >=20 > 16 bytes per process is kinda spendy, but I want to keep > lru behavior, which mem_score_adj does not allow. When a supervisor, > like Android's user input is keeping track this can be done in user-space. > It could be pulled out of task_struct if an cross-indexing additional > red-black tree is added to support pid-based lookup. Having android-like system for low memory killing might be interesting... but rather than throwing around patches maybe there should be discussion on lkml how the interface should look like, first? Pavel --=20 (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo= g.html --ikeVEW9yuYc//A+q Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAloMrZgACgkQMOfwapXb+vKnXgCbBGijGyq8Vy0Yl4B7PfXscOsS vUIAoLY3qUULJZwBqFbFLc9t+R+7LQvv =wJxX -----END PGP SIGNATURE----- --ikeVEW9yuYc//A+q--