From nobody Wed Nov 5 17:25:26 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zoho.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1496790839935526.0718093856082; Tue, 6 Jun 2017 16:13:59 -0700 (PDT) Received: from localhost ([::1]:40389 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dINfi-00057C-Dt for importer@patchew.org; Tue, 06 Jun 2017 19:13:58 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42240) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dINeL-0003wY-O2 for qemu-devel@nongnu.org; Tue, 06 Jun 2017 19:12:34 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dINeI-0002IB-J1 for qemu-devel@nongnu.org; Tue, 06 Jun 2017 19:12:33 -0400 Received: from out1-smtp.messagingengine.com ([66.111.4.25]:56951) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dINeI-0002Gl-0o for qemu-devel@nongnu.org; Tue, 06 Jun 2017 19:12:30 -0400 Received: from compute4.internal (compute4.nyi.internal [10.202.2.44]) by mailout.nyi.internal (Postfix) with ESMTP id 7AB3C20E0E; Tue, 6 Jun 2017 19:12:27 -0400 (EDT) Received: from frontend2 ([10.202.2.161]) by compute4.internal (MEProxy); Tue, 06 Jun 2017 19:12:27 -0400 Received: from localhost (flamenco.cs.columbia.edu [128.59.20.216]) by mail.messagingengine.com (Postfix) with ESMTPA id 03AF2248B4; Tue, 6 Jun 2017 19:12:27 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=braap.org; h=cc :date:from:in-reply-to:message-id:references:subject:to :x-me-sender:x-me-sender:x-sasl-enc:x-sasl-enc; s=mesmtp; bh=BFW w2FRbh2R6Bs6ruhrOo2EK1/z1ky9sG4TcqlwgizI=; b=vsjkRuROix0Qo3O75pn s/K+idhHjAiCyexvDvfmRAnBkfYy0mP+vcmNpnPHA22IId+ryztJf1+hLjW13VX/ Ez386dWc+PjZ9bV3uTAFRNwzw8uHA8xiATavrZQGvpIxEJEZ7Ed5H3hiWs/iOMa8 adEubAkvMnwYo5y7jgH792VE= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:date:from:in-reply-to:message-id :references:subject:to:x-me-sender:x-me-sender:x-sasl-enc :x-sasl-enc; s=fm1; bh=BFWw2FRbh2R6Bs6ruhrOo2EK1/z1ky9sG4Tcqlwgi zI=; b=S3vPP7FTCQdh4iXzuZrtCTyKKXaoucAwN4TmrTtbxwH3fkBSNtDhOxiSO 906PEs8/zDYfAhHve9Bz3Aneq+HXWnF3NabM4kCDgos4IzRDqnnjT2c3uR6rYvcJ Eqp7grsRvUejI6uuu1Xr/z+kmQKzl4Ddw0pDngD8uMvlEv3Tm8+hynSt0kDT05Cl sN/620JbQvMf9lcMiRCm+OIStTFGk/ueQDa77FPMzaN/KYujne6eaCoZDk7UxSaK +SRUn7fsa1yFovwAbWv9KZ71on0b9EcIqYS1473sXBj4UqOdaDmPS9uh19a/xDYs z7cIjFvuWjjoQ4EO/1yOLGeZGWrUg== X-ME-Sender: X-Sasl-enc: g2V2Vrds5rBzfIJWu1hEipRtwVmUH6T/sqPfmr/B1z9p 1496790747 From: "Emilio G. Cota" To: qemu-devel@nongnu.org Date: Tue, 6 Jun 2017 19:12:24 -0400 Message-Id: <1496790745-314-2-git-send-email-cota@braap.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1496790745-314-1-git-send-email-cota@braap.org> References: <1496790745-314-1-git-send-email-cota@braap.org> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 66.111.4.25 Subject: [Qemu-devel] [PATCH v3 1/2] util: add cacheinfo X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Maydell , Geert Martin Ijewski , Paolo Bonzini , Pranith Kumar , alex.bennee@linaro.org, Richard Henderson Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Add helpers to gather cache info from the host at init-time. For now, only export the host's I/D cache line sizes, which we will use to improve cache locality to avoid false sharing. Suggested-by: Richard Henderson Suggested-by: Geert Martin Ijewski Tested-by: Geert Martin Ijewski Signed-off-by: Emilio G. Cota --- include/qemu/osdep.h | 3 + util/Makefile.objs | 1 + util/cacheinfo.c | 158 +++++++++++++++++++++++++++++++++++++++++++++++= ++++ 3 files changed, 162 insertions(+) create mode 100644 util/cacheinfo.c diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h index 1c9f5e2..ee43521 100644 --- a/include/qemu/osdep.h +++ b/include/qemu/osdep.h @@ -470,4 +470,7 @@ char *qemu_get_pid_name(pid_t pid); */ pid_t qemu_fork(Error **errp); =20 +extern int qemu_icache_linesize; +extern int qemu_dcache_linesize; + #endif diff --git a/util/Makefile.objs b/util/Makefile.objs index c6205eb..94d9477 100644 --- a/util/Makefile.objs +++ b/util/Makefile.objs @@ -20,6 +20,7 @@ util-obj-y +=3D host-utils.o util-obj-y +=3D bitmap.o bitops.o hbitmap.o util-obj-y +=3D fifo8.o util-obj-y +=3D acl.o +util-obj-y +=3D cacheinfo.o util-obj-y +=3D error.o qemu-error.o util-obj-y +=3D id.o util-obj-y +=3D iov.o qemu-config.o qemu-sockets.o uri.o notify.o diff --git a/util/cacheinfo.c b/util/cacheinfo.c new file mode 100644 index 0000000..8c52c77 --- /dev/null +++ b/util/cacheinfo.c @@ -0,0 +1,158 @@ +/* + * cacheinfo.c - helpers to query the host about its caches + * + * Copyright (C) 2017, Emilio G. Cota + * License: GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + */ + +#include "qemu/osdep.h" + +int qemu_icache_linesize =3D 64; +int qemu_dcache_linesize =3D 64; + +#ifdef _WIN32 +static unsigned int linesize_win(PROCESSOR_CACHE_TYPE type) +{ + PSYSTEM_LOGICAL_PROCESSOR_INFORMATION buf; + DWORD size =3D 0; + unsigned int ret =3D 0; + BOOL success; + size_t n; + size_t i; + + success =3D GetLogicalProcessorInformation(0, &size); + if (success || GetLastError() !=3D ERROR_INSUFFICIENT_BUF) { + return 0; + } + buf =3D (PSYSTEM_LOGICAL_PROCESSOR_INFORMATION)g_malloc0(size); + if (!GetLogicalProcessorInformation(buf, &size)) { + goto out; + } + + n =3D size / sizeof(SYSTEM_LOGICAL_PROCESSOR_INFORMATION); + for (i =3D 0; i < n; i++) { + if (buf[i].Relationship =3D=3D RelationCache && + buf[i].Cache.Level =3D=3D 1 && + (buf[i].Cache.Type =3D=3D CacheUnified || + buf[i].Cache.Type =3D=3D type)) { + ret =3D buf[i].Cache.LineSize; + break; + } + } + out: + g_free(buf); + return ret; +} +#endif + +#ifdef __APPLE__ +#include + +unsigned int linesize_apple(void) +{ + unsigned long bytes; + size_t len =3D sizeof(bytes); + + /* There's only a single sysctl for both I/D cache line sizes */ + if (sysctlbyname("hw.cachelinesize", &bytes, &len, NULL, 0)) { + return 0; + } + return bytes; +} +#endif + +static void icache_info(void) +{ + #ifdef _SC_LEVEL1_ICACHE_LINESIZE + { + long x =3D sysconf(_SC_LEVEL1_ICACHE_LINESIZE); + + if (x > 0) { + qemu_icache_linesize =3D x; + return; + } + } + #endif + #ifdef AT_ICACHEBSIZE + /* glibc does not always export this through sysconf, e.g. on PPC */ + { + unsigned long x =3D qemu_getauxval(AT_ICACHEBSIZE); + + if (x > 0) { + qemu_icache_linesize =3D x; + return; + } + } + #endif + #ifdef _WIN32 + { + unsigned int x =3D linesize_win(CacheInstruction); + + if (x > 0) { + qemu_icache_linesize =3D x; + return; + } + } + #endif + #ifdef __APPLE__ + { + unsigned int x =3D linesize_apple(); + + if (x > 0) { + qemu_icache_linesize =3D x; + return; + } + } + #endif +} + +static void dcache_info(void) +{ + #ifdef _SC_LEVEL1_DCACHE_LINESIZE + { + long x =3D sysconf(_SC_LEVEL1_DCACHE_LINESIZE); + + if (x > 0) { + qemu_dcache_linesize =3D x; + return; + } + } + #endif + #ifdef AT_DCACHEBSIZE + { + unsigned long x =3D qemu_getauxval(AT_DCACHEBSIZE); + + if (x > 0) { + qemu_dcache_linesize =3D x; + return; + } + } + #endif + #ifdef _WIN32 + { + unsigned int x =3D linesize_win(CacheData); + + if (x > 0) { + qemu_dcache_linesize =3D x; + return; + } + } + #endif + #ifdef __APPLE__ + { + unsigned int x =3D linesize_apple(); + + if (x > 0) { + qemu_dcache_linesize =3D x; + return; + } + } + #endif +} + +static void __attribute__((constructor)) cacheinfo_init(void) +{ + icache_info(); + dcache_info(); +} --=20 2.7.4