Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756651AbcCRUln (ORCPT ); Fri, 18 Mar 2016 16:41:43 -0400 Received: from outbound.smtp.vt.edu ([198.82.183.121]:43914 "EHLO omr2.cc.vt.edu" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754494AbcCRUlf (ORCPT ); Fri, 18 Mar 2016 16:41:35 -0400 X-Mailer: exmh version 2.8.0 04/21/2012 with nmh-1.6+dev To: Andrey Ryabinin , Alexander Potapenko Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: KASAN overhead? From: Valdis Kletnieks Mime-Version: 1.0 Content-Type: multipart/signed; boundary="==_Exmh_1458333684_2471P"; micalg=pgp-sha1; protocol="application/pgp-signature" Content-Transfer-Encoding: 7bit Date: Fri, 18 Mar 2016 16:41:24 -0400 Message-ID: <7300.1458333684@turing-police.cc.vt.edu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3149 Lines: 78 --==_Exmh_1458333684_2471P Content-Type: text/plain; charset="us-ascii" Content-Id: <7276.1458333675.1@turing-police.cc.vt.edu> Content-Transfer-Encoding: quoted-printable So I built linux-next next-20160417 with KASAN enabled: CONFIG_KASAN_SHADOW_OFFSET=3D0xdffffc0000000000 CONFIG_HAVE_ARCH_KASAN=3Dy = CONFIG_KASAN=3Dy = # CONFIG_KASAN_OUTLINE is not set CONFIG_KASAN_INLINE=3Dy = CONFIG_TEST_KASAN=3Dm and saw an *amazing* slowdown. For comparison, here is the time taken to reach various points in the dmesg: % grep -i free dmesg.0317* dmesg.0317:[ 1.560907] Freeing SMP alternatives memory: 28K (ffffffff93= d3e000 - ffffffff93d45000) dmesg.0317:[ 12.041550] Freeing initrd memory: 10432K (ffff88003f5cb000 = - ffff88003fffb000) dmesg.0317:[ 16.458451] ata1.00: ACPI cmd f5/00:00:00:00:00:00 (SECURITY= FREEZE LOCK) filtered out dmesg.0317:[ 16.545603] ata1.00: ACPI cmd f5/00:00:00:00:00:00 (SECURITY= FREEZE LOCK) filtered out dmesg.0317:[ 17.818934] Freeing unused kernel memory: 1628K (ffffffff93b= a7000 - ffffffff93d3e000) dmesg.0317:[ 17.820234] Freeing unused kernel memory: 1584K (ffff880012c= 74000 - ffff880012e00000) dmesg.0317:[ 17.828426] Freeing unused kernel memory: 1524K (ffff8800134= 83000 - ffff880013600000) dmesg.0317-nokasan:[ 0.028821] Freeing SMP alternatives memory: 28K (ff= ffffffaf104000 - ffffffffaf10b000) dmesg.0317-nokasan:[ 1.587232] Freeing initrd memory: 10432K (ffff88003= f5cb000 - ffff88003fffb000) dmesg.0317-nokasan:[ 2.433557] ata1.00: ACPI cmd f5/00:00:00:00:00:00 (= SECURITY FREEZE LOCK) filtered out dmesg.0317-nokasan:[ 2.439411] ata1.00: ACPI cmd f5/00:00:00:00:00:00 (= SECURITY FREEZE LOCK) filtered out dmesg.0317-nokasan:[ 2.488113] Freeing unused kernel memory: 1324K (fff= fffffaefb9000 - ffffffffaf104000) dmesg.0317-nokasan:[ 2.488518] Freeing unused kernel memory: 88K (ffff8= 8002e9ea000 - ffff88002ea00000) dmesg.0317-nokasan:[ 2.489490] Freeing unused kernel memory: 388K (ffff= 88002ed9f000 - ffff88002ee00000) Only config difference was changing to CONFIG_KASAN=3Dn. Is this level of slowdown expected? Or is my kernel unexpectedly off in th= e weeds? --==_Exmh_1458333684_2471P Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 Comment: Exmh version 2.5 07/13/2001 iQIVAwUBVuxn9AdmEQWDXROgAQKAbhAAvonR2LPjBviulz1xHSXgJ9tTvMmfAlrU anvPgBBp6iW9bVk/7KtPyS1mtoYo0uc+T8XUCbykQFzyh+JTzuJsvNtVqREq2LwE Ao6RbX/NyHYtYS/Vtx2lg9X3X7RiURgTXnAN4AmrnqxLVL8L3LzwCzWIsqHrcXHi Ds2QleZuX3f5wqTMBtYr89XbHyFyJfHyc8/giLKaD/aOmubTrGkcMGWfZqxOhmZj NoDoN0SsTtOfYiixQP+r7yANBMw3g63T59TaVnxArdgAFAx+IrqffOkbXqiNtRgS 7gh6iso6cmg3gGTh5J2QG7ZprzyCfCsI3VQ6h9oRxKlFzId/1DCcMGKowSSYsqhN 2f3DNMghMMHmlcuNkeTf5D3n1L+egzoS1Cr5EmpIQ2gi30mZbfidtoRSY7ljGjg6 OezzHMdbWqkNSL58RYyGSzKcVQU/4SnTK6jMrV5JcoYqwlfkpX/PCs9mVCbwWr++ Cy8KX/G8RB0mtvnmNMqCGMC4A2riLEQEoj1DjcSy12v0m8fzx/mouYzPX2ThHfLR iBIRLXrcBKm3Mrb0F51066He3s8QbixJIPRlK45uQcLN2sVzGY8WOzzM6cUfhnm0 Y9ujoeeJufoEEtjf8gRQHGWgEJBOZDvV8dBPtJOdcuXa3B5XeqHPT/7UeZeWHi4/ 5MnGrYj/eg4= =oxXs -----END PGP SIGNATURE----- --==_Exmh_1458333684_2471P--