Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753874AbbDGL0k (ORCPT ); Tue, 7 Apr 2015 07:26:40 -0400 Received: from mail9.hitachi.co.jp ([133.145.228.44]:48069 "EHLO mail9.hitachi.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752824AbbDGL0g (ORCPT ); Tue, 7 Apr 2015 07:26:36 -0400 Message-ID: <5523BEE5.4000709@hitachi.com> Date: Tue, 07 Apr 2015 20:26:29 +0900 From: Masami Hiramatsu Organization: Hitachi, Ltd., Japan User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:13.0) Gecko/20120614 Thunderbird/13.0.1 MIME-Version: 1.0 To: Steven Rostedt CC: linux-kernel@vger.kernel.org, Ingo Molnar , Andrew Morton , Arnaldo Carvalho de Melo , Namhyung Kim , Mathieu Desnoyers Subject: Re: [PATCH 00/18 v3] tracing: Use TRACE_DEFINE_ENUM() to show enum values References: <20150403013802.220157513@goodmis.org> In-Reply-To: <20150403013802.220157513@goodmis.org> Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6075 Lines: 148 (2015/04/03 10:38), Steven Rostedt wrote: > As there are many tracepoints that use __print_symbolic() to translate > numbers into ASCII strings, and several of these translate enums as > well, it causes a problem for user space tools that read the tracepoint > format files and have to translate the binary data to their associated > strings. > > For example, with the tlb_flush tracepoint, we have this in the format > file: > > print fmt: "pages:%ld reason:%s (%d)", REC->pages, > __print_symbolic(REC->reason, > { TLB_FLUSH_ON_TASK_SWITCH, "flush on task switch" }, > { TLB_REMOTE_SHOOTDOWN, "remote shootdown" }, > { TLB_LOCAL_SHOOTDOWN, "local shootdown" }, > { TLB_LOCAL_MM_SHOOTDOWN, "local mm shootdown" }), REC->reason > > Now, userspace does not know what the value of TLB_REMOTE_SHOOTDOWN is. > To solve this, a new macro is created as a helper to allow tracepoints > to export enums they use to userspace. This macro is called, > TRACE_DEFINE_ENUM(), such that > > TRACE_DEFINE_ENUM(TLB_REMOTE_SHOOTDOWN); > > will convert the "print fmt"s in the format files to its actual value > and no longer display the enum name. > > On boot up (or module load), the enums saved via TRACE_DEFINE_ENUM() > will be searched for in the TP_printk()s of the tracepoints. Logic > knows enough to ignore quoted text. > > And the output of the tlb_flush format is now: > > print fmt: "pages:%ld reason:%s (%d)", REC->pages, > __print_symbolic(REC->reason, > { 0, "flush on task switch" }, > { 1, "remote shootdown" }, > { 2, "local shootdown" }, > { 3, "local mm shootdown" }), REC->reason > > And userspace tools can easily parse that without special handling. > > For debugging, if CONFIG_TRACE_ENUM_MAP_FILE is enabled, a file is added > in the tracing directory to show what enums were added, their values and > the TRACE_SYSTEM that added them: > > # cat /sys/kernel/debug/tracing/enum_map > TLB_LOCAL_MM_SHOOTDOWN 3 (tlb) > TLB_LOCAL_SHOOTDOWN 2 (tlb) > TLB_REMOTE_SHOOTDOWN 1 (tlb) > TLB_FLUSH_ON_TASK_SWITCH 0 (tlb) I've reviewed all patches in this series and tested it. Reviewed-by: Masami Hiramatsu Tested-by: Masami Hiramatsu for all the patches in this series. However, I've also found that the __print_symbolic()s in events/scsi/scsi_dispatch_cmd_*/format events/xfs/xfs_map_blocks_alloc/format events/xfs/xfs_get_blocks_found/format events/xfs/xfs_get_blocks_alloc/format events/power/pm_qos_*/format are not fixed yet. Thank you, > > -- Steve > > Local SHA1: 6689c330e3a60defc4c89da17cf5d561649bc55b > > > Steven Rostedt (1): > tracing/drm: Remove unused TRACE_SYSTEM_STRING define > > Steven Rostedt (Red Hat) (17): > tracing: Add TRACE_SYSTEM_VAR to intel-sst > tracing: Add TRACE_SYSTEM_VAR to kvm-s390 > tracing: Add TRACE_SYSTEM_VAR to xhci-hcd > tracing: Give system name a pointer > tracing: Update trace-event-sample with TRACE_SYSTEM_VAR documentation > tracing: Add TRACE_DEFINE_ENUM() macro to map enums to their values > tracing: Allow for modules to convert their enums to values > tracing/samples: Update the trace-event-sample.h with TRACE_DEFINE_ENUM() > x86/tlb/trace: Export enums in used by tlb_flush tracepoint > net/9p/tracing: Export enums in tracepoints to userspace > f2fs: Export the enums in the tracepoints to userspace > irq/tracing: Export enums in tracepoints to user space > mm: tracing: Export enums in tracepoints to user space > SUNRPC: Export enums in tracepoints to user space > v4l: Export enums used by tracepoints to user space > writeback: Export enums used by tracepoint to user space > tracing: Add enum_map file to show enums that have been mapped > > ---- > arch/s390/kvm/trace-s390.h | 7 + > drivers/gpu/drm/drm_trace.h | 1 - > drivers/gpu/drm/i915/i915_trace.h | 1 - > drivers/gpu/drm/radeon/radeon_trace.h | 1 - > drivers/usb/host/xhci-trace.h | 7 + > include/asm-generic/vmlinux.lds.h | 5 +- > include/linux/ftrace_event.h | 4 +- > include/linux/module.h | 2 + > include/linux/tracepoint.h | 8 + > include/trace/events/9p.h | 157 ++++++++------- > include/trace/events/f2fs.h | 30 +++ > include/trace/events/intel-sst.h | 7 + > include/trace/events/irq.h | 39 ++-- > include/trace/events/migrate.h | 42 +++- > include/trace/events/sunrpc.h | 62 ++++-- > include/trace/events/tlb.h | 30 ++- > include/trace/events/v4l2.h | 75 ++++--- > include/trace/events/writeback.h | 33 +++- > include/trace/ftrace.h | 41 +++- > kernel/module.c | 3 + > kernel/trace/Kconfig | 28 +++ > kernel/trace/trace.c | 304 ++++++++++++++++++++++++++++- > kernel/trace/trace.h | 2 + > kernel/trace/trace_events.c | 121 +++++++++++- > samples/trace_events/trace-events-sample.h | 84 +++++++- > 25 files changed, 932 insertions(+), 162 deletions(-) > -- > 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/ > > -- Masami HIRAMATSU Linux Technology Research Center, System Productivity Research Dept. Center for Technology Innovation - Systems Engineering Hitachi, Ltd., Research & Development Group E-mail: masami.hiramatsu.pt@hitachi.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/