From mboxrd@z Thu Jan 1 00:00:00 1970 From: Robert Richter Subject: Re: [PATCH] ARM: oprofile: Always allow backtraces Date: Thu, 20 Jan 2011 10:52:39 +0100 Message-ID: <20110120095239.GT21401@erda.amd.com> References: <1295470473-1095-1-git-send-email-kauppi@papupata.org> <000101cbb886$582f1480$088d3d80$@deacon@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Return-path: Received: from va3ehsobe006.messaging.microsoft.com ([216.32.180.16]:5848 "EHLO VA3EHSOBE009.bigfish.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755242Ab1ATJwp (ORCPT ); Thu, 20 Jan 2011 04:52:45 -0500 Content-Disposition: inline In-Reply-To: <000101cbb886$582f1480$088d3d80$@deacon@arm.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Will Deacon Cc: 'Ari Kauppi' , "linux-arm-kernel@lists.infradead.org" , "linux-omap@vger.kernel.org" , Richard Purdie , Matt Fleming On 20.01.11 04:42:24, Will Deacon wrote: > Hi Ari, > > > Always allow backtrace when using oprofile on ARM, even if a PMU > > isn't present. > > > > Restores functionality originally introduced in > > 1b7b56982fdcd9d85effd76f3928cf5d6eb26155 by Richard Purdie. > > Well spotted, I'd forgotten we still want this for timer mode. > Comments inline. > > > diff --git a/arch/arm/oprofile/common.c b/arch/arm/oprofile/common.c > > index 8aa9744..a23e5ae 100644 > > --- a/arch/arm/oprofile/common.c > > +++ b/arch/arm/oprofile/common.c > > @@ -46,6 +46,7 @@ char *op_name_from_perf_id(void) > > return NULL; > > } > > } > > +#endif > > > > static int report_trace(struct stackframe *frame, void *d) > > { > > @@ -109,6 +110,7 @@ static void arm_backtrace(struct pt_regs * const regs, unsigned int depth) > > tail = user_backtrace(tail); > > } > > > > +#ifdef CONFIG_HW_PERF_EVENTS > > Can you reorder the backtrace stuff so that we don't need the extra > #endif/#ifdef please? I would like to go even further, see the diff below. -Robert --- arch/arm/oprofile/common.c | 45 ++++++++++++++++++++++++------------------- 1 files changed, 25 insertions(+), 20 deletions(-) diff --git a/arch/arm/oprofile/common.c b/arch/arm/oprofile/common.c index 8aa9744..916aa2e 100644 --- a/arch/arm/oprofile/common.c +++ b/arch/arm/oprofile/common.c @@ -47,18 +47,6 @@ char *op_name_from_perf_id(void) } } -static int report_trace(struct stackframe *frame, void *d) -{ - unsigned int *depth = d; - - if (*depth) { - oprofile_add_trace(frame->pc); - (*depth)--; - } - - return *depth == 0; -} - /* * The registers we're interested in are at the end of the variable * length saved register structure. The fp points at the end of this @@ -91,6 +79,30 @@ static struct frame_tail* user_backtrace(struct frame_tail *tail) return buftail[0].fp-1; } +#else + +static int oprofile_arch_init(struct oprofile_operations *ops) +{ + pr_info("oprofile: hardware counters not available\n"); + return -ENODEV; +} + +static void oprofile_arch_exit(void) { } + +#endif /* CONFIG_HW_PERF_EVENTS */ + +static int report_trace(struct stackframe *frame, void *d) +{ + unsigned int *depth = d; + + if (*depth) { + oprofile_add_trace(frame->pc); + (*depth)--; + } + + return *depth == 0; +} + static void arm_backtrace(struct pt_regs * const regs, unsigned int depth) { struct frame_tail *tail = ((struct frame_tail *) regs->ARM_fp) - 1; @@ -111,6 +123,7 @@ static void arm_backtrace(struct pt_regs * const regs, unsigned int depth) int __init oprofile_arch_init(struct oprofile_operations *ops) { + /* provide backtrace support also in timer mode: */ ops->backtrace = arm_backtrace; return oprofile_perf_init(ops); @@ -120,11 +133,3 @@ void __exit oprofile_arch_exit(void) { oprofile_perf_exit(); } -#else -int __init oprofile_arch_init(struct oprofile_operations *ops) -{ - pr_info("oprofile: hardware counters not available\n"); - return -ENODEV; -} -void __exit oprofile_arch_exit(void) {} -#endif /* CONFIG_HW_PERF_EVENTS */ -- 1.7.3.4 -- Advanced Micro Devices, Inc. Operating System Research Center