From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christopher Baines Subject: Performance issues with /gnu/store in virtual machines Date: Thu, 17 Aug 2017 21:05:47 +0100 Message-ID: <20170817210547.3fafde57@cbaines.net> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; boundary="Sig_/PnrxqEAsa619NPVkd8F0z2s"; protocol="application/pgp-signature" Return-path: Received: from eggs.gnu.org ([2001:4830:134:3::10]:35097) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1diR3G-0001PH-Hv for help-guix@gnu.org; Thu, 17 Aug 2017 16:05:59 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1diR3B-0006dX-Im for help-guix@gnu.org; Thu, 17 Aug 2017 16:05:58 -0400 Received: from li622-129.members.linode.com ([212.71.249.129]:56652 helo=mira.cbaines.net) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1diR3B-0006bv-9u for help-guix@gnu.org; Thu, 17 Aug 2017 16:05:53 -0400 Received: from localhost (cpc102582-walt20-2-0-cust14.13-2.cable.virginm.net [86.27.34.15]) by mira.cbaines.net (Postfix) with ESMTPSA id E00FE16FE88 for ; Thu, 17 Aug 2017 21:05:50 +0100 (BST) List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: help-guix-bounces+gcggh-help-guix=m.gmane.org@gnu.org Sender: "Help-Guix" To: help-guix@gnu.org --Sig_/PnrxqEAsa619NPVkd8F0z2s Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable Hey, So I was trying out using VMs created through Guix for more things, particularly as they can be run as part of derivations, e.g. the system tests for Guix. However, I'm seeing anything that does I/O performing very poorly compared with the host system. See the system call profiles from strace below, for the following command: strace -c find /gnu/store/*-guile* -name guile | wc -l Is anyone else having difficulties with this, or have any experience with performance tuning for the software in use here? Thanks, Chris On the host system, I see the following performance: % time seconds usecs/call calls errors syscall ------ ----------- ----------- --------- --------- ---------------- 76.23 0.001286 0 31978 fcntl 10.20 0.000172 0 6974 getdents 7.53 0.000127 0 18673 newfstatat 3.32 0.000056 0 14208 close 1.60 0.000027 0 3872 fstat 1.13 0.000019 0 3853 openat 0.00 0.000000 0 20 read 0.00 0.000000 0 4 write 0.00 0.000000 0 69 50 open 0.00 0.000000 0 6 6 stat 0.00 0.000000 0 21 mmap 0.00 0.000000 0 8 mprotect 0.00 0.000000 0 33 brk 0.00 0.000000 0 2 1 ioctl 0.00 0.000000 0 1 1 access 0.00 0.000000 0 1 execve 0.00 0.000000 0 1 uname 0.00 0.000000 0 1 fchdir 0.00 0.000000 0 1 arch_prctl ------ ----------- ----------- --------- --------- ---------------- 100.00 0.001687 79726 58 total Within the VM, I see the following performance: % time seconds usecs/call calls errors syscall ------ ----------- ----------- --------- --------- ---------------- 59.83 0.851601 46 18673 newfstatat 13.56 0.193014 50 3853 openat 10.88 0.154935 22 6974 getdents 7.95 0.113196 8 14208 close 4.00 0.056956 15 3872 fstat 3.58 0.050908 2 31978 fcntl 0.14 0.002051 66 31 12 open 0.02 0.000232 12 20 read 0.01 0.000199 7 30 brk 0.01 0.000107 18 6 6 stat 0.01 0.000076 4 21 mmap 0.00 0.000045 6 8 mprotect 0.00 0.000030 8 4 write 0.00 0.000018 18 1 1 access 0.00 0.000006 3 2 1 ioctl 0.00 0.000004 4 1 execve 0.00 0.000003 3 1 uname 0.00 0.000003 3 1 fchdir 0.00 0.000001 1 1 arch_prctl ------ ----------- ----------- --------- --------- ---------------- 100.00 1.423385 79685 20 total --Sig_/PnrxqEAsa619NPVkd8F0z2s Content-Type: application/pgp-signature Content-Description: OpenPGP digital signature -----BEGIN PGP SIGNATURE----- iQKTBAEBCgB9FiEEPonu50WOcg2XVOCyXiijOwuE9XcFAlmV9xtfFIAAAAAALgAo aXNzdWVyLWZwckBub3RhdGlvbnMub3BlbnBncC5maWZ0aGhvcnNlbWFuLm5ldDNF ODlFRUU3NDU4RTcyMEQ5NzU0RTBCMjVFMjhBMzNCMEI4NEY1NzcACgkQXiijOwuE 9XeEow//bdGgFcnibiiOC/dNlJQLJ5Zs/kGpWjR3ypDIoLcTn3abxRrtpARAssnE CoLDT169Glc3+TWfri+M7TIq6vJEfAQpSC5ZRFaNr7DTFgasR02dXm12yzdnbXvH 7dJMUFaU/uaxilteGTC4okqJNdJKJf7fQskuSTAmfdbjousyyDLrIbfT5F9v2oXp WHBsX+wnUF+NOacU7SmtHCj/vr4rleGaabfL1zPSJryd9KwRJpwVEYkWGhyq6bor JSnHNa8GarvM6614pbRecWwIp+JsH6lsCIoWtIdbYXDu5a6rJSs5vV/3ubUMHjiz FLYkPlAvyDvTexwWiJgeoBm/O9Z5FQU0NDNyhso+OjleD9WHI+p+ZRe7Qa66EB44 pq7m2cVNDFk4F6kqm329V+TjM8U63tWxJNNtnJGH/lt5Su2CPAE2n1Naoaw1FMNZ vQ/gRaiJCOINMlcOIFmU3xPCa2idFuuJi2HYBwcgu7SIg8wKD2woLQzo8MLpp1Z7 09GF3deIUCYeLiTPx9eNnNZgIdmn9MSuKsNtDsp7alHSEKHdBsUIrSb1kgL0TvQE qhj6HedjRTs8uct+fajFh0oIzFMNB+bfSO4QKYzsiImg/toDKTtyHao4VtNsdNEA 9pApdQumzri76T42urrCcAAI3cyb5MZ5dnnPNX+yW2Cc9EShALw= =Bgc+ -----END PGP SIGNATURE----- --Sig_/PnrxqEAsa619NPVkd8F0z2s--