From mboxrd@z Thu Jan 1 00:00:00 1970 From: Shuah Khan Subject: Re: [PATCH 1/4] ACPI: Add acpi_pr_() interfaces Date: Wed, 18 Jul 2012 15:59:31 -0600 Message-ID: <1342648771.5138.37.camel@lorien2> References: <1342644027-19559-1-git-send-email-toshi.kani@hp.com> <1342644027-19559-2-git-send-email-toshi.kani@hp.com> Reply-To: shuah.khan@hp.com Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: Received: from g4t0016.houston.hp.com ([15.201.24.19]:7867 "EHLO g4t0016.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751489Ab2GRV7e (ORCPT ); Wed, 18 Jul 2012 17:59:34 -0400 In-Reply-To: <1342644027-19559-2-git-send-email-toshi.kani@hp.com> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Toshi Kani Cc: lenb@kernel.org, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, bhelgaas@google.com, isimatu.yasuaki@jp.fujitsu.com, liuj97@gmail.com, srivatsa.bhat@linux.vnet.ibm.com, prarit@redhat.com, imammedo@redhat.com, vijaymohan.pandarathil@hp.com, shuahkhan@gmail.com On Wed, 2012-07-18 at 14:40 -0600, Toshi Kani wrote: > This patch introduces acpi_pr_(), where is a message > level such as err/warn/info, to support improved logging messages > for ACPI, esp. in hotplug operations. acpi_pr_() appends > "ACPI" prefix and ACPI object path to the messages. This improves > diagnostics in hotplug operations since it identifies an object that > caused an issue in a log file. > > acpi_pr_() takes acpi_handle as an argument, which is passed > to ACPI hotplug notify handlers from the ACPI CA. Therefore, it is > always available unlike other kernel objects, such as device. > > For example, the statement below > acpi_pr_err(handle, "Device don't exist, dropping EJECT\n"); > logs an error message like this: > ACPI: \_SB_.SCK4.CPU4: Device don't exist, dropping EJECT > > Signed-off-by: Toshi Kani > --- > drivers/acpi/utils.c | 32 ++++++++++++++++++++++++++++++++ > include/acpi/acpi_bus.h | 18 ++++++++++++++++++ > 2 files changed, 50 insertions(+), 0 deletions(-) > > diff --git a/drivers/acpi/utils.c b/drivers/acpi/utils.c > index 3e87c9c..4097266 100644 > --- a/drivers/acpi/utils.c > +++ b/drivers/acpi/utils.c > @@ -454,3 +454,35 @@ acpi_evaluate_hotplug_ost(acpi_handle handle, u32 source_event, > #endif > } > EXPORT_SYMBOL(acpi_evaluate_hotplug_ost); > + > +/** > + * acpi_printk: Print messages with ACPI prefix and object path > + * > + * This function is intended to be called through acpi_pr_ macros. > + */ > +void > +acpi_printk(const char *level, acpi_handle handle, const char *fmt, ...) > +{ > + struct va_format vaf; > + va_list args; > + struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER}; > + char *path; > + acpi_status ret; > + > + va_start(args, fmt); > + > + vaf.fmt = fmt; > + vaf.va = &args; > + > + ret = acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer); One big problem I see with this approach is now each acpi_printk() will result in a call to acpi_get_name() which will invoke several ACPI calls, including a call to acpi_ut_initialize_buffer() which allocates buffer. Is this really warranted? What is the performance impact of this change? -- Shuah