Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753929AbYFIWha (ORCPT ); Mon, 9 Jun 2008 18:37:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1761586AbYFIWeQ (ORCPT ); Mon, 9 Jun 2008 18:34:16 -0400 Received: from hu-out-0506.google.com ([72.14.214.239]:26395 "EHLO hu-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760290AbYFIWeL (ORCPT ); Mon, 9 Jun 2008 18:34:11 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=googlemail.com; s=gamma; h=to:subject:from:date:message-id; b=LiPrh5ELnjlWMSMyN3CU2iWXz42HVsZVwDiHVVjUaSPENR7jkMuG+FiPXkoH7gaWmD 5kJzWUzEAyT41kfzWWBNQ47W6o44HkCYNcnBef9Ok/L+/sBVhjBJ+4WgTAAqmwxfIZOZ PQONkVO1fKbj1rDdLBq7I9jtzp0Hrcoq8a9ZI= To: linux-kernel@vger.kernel.org Subject: [patch 08/21] perfmon2 minimal: X86 OProfile hooks From: eranian@googlemail.com Date: Mon, 09 Jun 2008 15:34:09 -0700 (PDT) Message-ID: <484dafe1.0af5660a.09d4.6269@mx.google.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4504 Lines: 180 Provides PMU access synchronization between Perfmon2 and OProfile. Both subsystems can be compiled in. Only one of them can be active at any one time. It is necessary to issue opcontrol --shutdown to terminate the OProfile session. Signed-off-by: Stephane Eranian -- Index: o/arch/x86/oprofile/nmi_int.c =================================================================== --- o.orig/arch/x86/oprofile/nmi_int.c 2008-06-04 22:36:10.000000000 +0200 +++ o/arch/x86/oprofile/nmi_int.c 2008-06-04 22:38:20.000000000 +0200 @@ -15,6 +15,7 @@ #include #include #include +#include #include #include #include @@ -191,12 +192,18 @@ int err = 0; int cpu; - if (!allocate_msrs()) + if (pfm_session_allcpus_acquire()) + return -EBUSY; + + if (!allocate_msrs()) { + pfm_session_allcpus_release(); return -ENOMEM; + } err = register_die_notifier(&profile_exceptions_nb); if (err) { free_msrs(); + pfm_session_allcpus_release(); return err; } @@ -275,6 +282,7 @@ unregister_die_notifier(&profile_exceptions_nb); model->shutdown(msrs); free_msrs(); + pfm_session_allcpus_release(); } static void nmi_cpu_start(void *dummy) Index: o/include/linux/perfmon_kern.h =================================================================== --- o.orig/include/linux/perfmon_kern.h 2008-06-04 22:38:13.000000000 +0200 +++ o/include/linux/perfmon_kern.h 2008-06-04 22:38:20.000000000 +0200 @@ -180,6 +180,9 @@ void pfm_interrupt_handler(unsigned long ip, struct pt_regs *regs); +int pfm_session_allcpus_acquire(void); +void pfm_session_allcpus_release(void); + static inline void pfm_exit_thread(void) { if (current->pfm_context) @@ -256,6 +259,8 @@ #define pfm_copy_thread(_t) do { } while (0) #define pfm_ctxsw_in(_p, _n) do { } while (0) #define pfm_ctxsw_out(_p, _n) do { } while (0) +#define pfm_session_allcpus_release() do { } while (0) +#define pfm_session_allcpus_acquire() (0) #endif /* CONFIG_PERFMON */ Index: o/perfmon/perfmon_res.c =================================================================== --- o.orig/perfmon/perfmon_res.c 2008-06-04 22:36:10.000000000 +0200 +++ o/perfmon/perfmon_res.c 2008-06-04 22:38:20.000000000 +0200 @@ -36,6 +36,7 @@ * 02111-1307 USA */ #include +#include #include #include "perfmon_priv.h" @@ -103,3 +104,87 @@ spin_unlock_irqrestore(&pfm_res_lock, flags); } + +/** + * pfm_session_allcpus_acquire - acquire per-cpu sessions on all available cpus + * + * currently used by Oprofile on X86 + */ +int pfm_session_allcpus_acquire(void) +{ + unsigned long flags; + u32 nsys_cpus, cpu; + int ret = -EBUSY; + + spin_lock_irqsave(&pfm_res_lock, flags); + + nsys_cpus = cpus_weight(pfm_res.sys_cpumask); + + PFM_DBG("in sys=%u task=%u", + nsys_cpus, + pfm_res.thread_sessions); + + if (nsys_cpus) { + PFM_DBG("already some system-wide sessions"); + goto abort; + } + + /* + * cannot mix system wide and per-task sessions + */ + if (pfm_res.thread_sessions) { + PFM_DBG("%u conflicting thread_sessions", + pfm_res.thread_sessions); + goto abort; + } + + for_each_online_cpu(cpu) { + cpu_set(cpu, pfm_res.sys_cpumask); + nsys_cpus++; + } + + PFM_DBG("out sys=%u task=%u", + nsys_cpus, + pfm_res.thread_sessions); + + ret = 0; +abort: + spin_unlock_irqrestore(&pfm_res_lock, flags); + + return ret; +} +EXPORT_SYMBOL(pfm_session_allcpus_acquire); + +/** + * pfm_session_allcpus_release - relase per-cpu sessions on all cpus + * + * currently used by Oprofile code + */ +void pfm_session_allcpus_release(void) +{ + unsigned long flags; + u32 nsys_cpus, cpu; + + spin_lock_irqsave(&pfm_res_lock, flags); + + nsys_cpus = cpus_weight(pfm_res.sys_cpumask); + + PFM_DBG("in sys=%u task=%u", + nsys_cpus, + pfm_res.thread_sessions); + + /* + * XXX: could use __cpus_clear() with nbits + */ + for_each_online_cpu(cpu) { + cpu_clear(cpu, pfm_res.sys_cpumask); + nsys_cpus--; + } + + PFM_DBG("out sys=%u task=%u", + nsys_cpus, + pfm_res.thread_sessions); + + spin_unlock_irqrestore(&pfm_res_lock, flags); +} +EXPORT_SYMBOL(pfm_session_allcpus_release); -- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/