Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752890Ab2FORIu (ORCPT ); Fri, 15 Jun 2012 13:08:50 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:44549 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751081Ab2FORIt (ORCPT ); Fri, 15 Jun 2012 13:08:49 -0400 Date: Fri, 15 Jun 2012 10:07:00 -0700 From: Anton Vorontsov To: Greg Kroah-Hartman , Kees Cook , Colin Cross , Tony Luck , Steven Rostedt , Frederic Weisbecker , Ingo Molnar Cc: Arnd Bergmann , John Stultz , Shuah Khan , arve@android.com, Rebecca Schultz Zavin , Jesper Juhl , Randy Dunlap , Stephen Boyd , Thomas Meyer , Andrew Morton , Marco Stornelli , WANG Cong , linux-kernel@vger.kernel.org, devel@driverdev.osuosl.org, linaro-kernel@lists.linaro.org, patches@linaro.org, kernel-team@android.com Subject: [PATCH v2 0/6] Function tracing support for pstore Message-ID: <20120615170659.GA4060@lizard> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2865 Lines: 63 Hi all, In v2: - Do not introduce a separate 'persistent' tracer, but introduce an option to the existing 'function' tracer. Rationale for this patch set: With this support kernel can save functions call chain log into a persistent ram buffer that can be decoded and dumped after reboot through pstore filesystem. It can be used to determine what function was last called before a hang or an unexpected reset (caused by, for example, a buggy driver that abuses HW). Here's a "nano howto", to get the idea: # mount -t debugfs debugfs /sys/kernel/debug/ # cd /sys/kernel/debug/tracing # echo function > current_tracer # echo 1 > options/func_pstore # reboot -f [...] # mount -t pstore pstore /mnt/ # tail /mnt/ftrace-ramoops 0 ffffffff8101ea64 ffffffff8101bcda native_apic_mem_read <- disconnect_bsp_APIC+0x6a/0xc0 0 ffffffff8101ea44 ffffffff8101bcf6 native_apic_mem_write <- disconnect_bsp_APIC+0x86/0xc0 0 ffffffff81020084 ffffffff8101a4b5 hpet_disable <- native_machine_shutdown+0x75/0x90 0 ffffffff81005f94 ffffffff8101a4bb iommu_shutdown_noop <- native_machine_shutdown+0x7b/0x90 0 ffffffff8101a6a1 ffffffff8101a437 native_machine_emergency_restart <- native_machine_restart+0x37/0x40 0 ffffffff811f9876 ffffffff8101a73a acpi_reboot <- native_machine_emergency_restart+0xaa/0x1e0 0 ffffffff8101a514 ffffffff8101a772 mach_reboot_fixups <- native_machine_emergency_restart+0xe2/0x1e0 0 ffffffff811d9c54 ffffffff8101a7a0 __const_udelay <- native_machine_emergency_restart+0x110/0x1e0 0 ffffffff811d9c34 ffffffff811d9c80 __delay <- __const_udelay+0x30/0x40 0 ffffffff811d9d14 ffffffff811d9c3f delay_tsc <- __delay+0xf/0x20 Mostly the code comes from trace_persistent.c driver found in the Android git tree, written by Colin Cross (according to sign-off history). I reworked the driver a little bit, and ported it to pstore subsystem. --- Documentation/ramoops.txt | 25 +++++++++ fs/pstore/Kconfig | 12 +++++ fs/pstore/Makefile | 6 +++ fs/pstore/ftrace.c | 35 +++++++++++++ fs/pstore/inode.c | 111 ++++++++++++++++++++++++++++++++++++++-- fs/pstore/internal.h | 49 ++++++++++++++++++ fs/pstore/platform.c | 12 ++++- fs/pstore/ram.c | 54 ++++++++++++++----- include/linux/pstore.h | 13 +++++ include/linux/pstore_ram.h | 1 + kernel/trace/trace.c | 7 +-- kernel/trace/trace_functions.c | 25 +++++++-- 12 files changed, 325 insertions(+), 25 deletions(-) -- Anton Vorontsov Email: cbouatmailru@gmail.com -- 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/