From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steven Rostedt Date: Fri, 01 Apr 2022 16:03:05 +0000 Subject: Re: [PATCH 1/3 v2] Docs: admin/kernel-parameters: edit a few boot options Message-Id: <20220401120305.00076d14@gandalf.local.home> List-Id: References: <20220401030927.12023-1-rdunlap@infradead.org> <20220401030927.12023-2-rdunlap@infradead.org> In-Reply-To: <20220401030927.12023-2-rdunlap@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Randy Dunlap Cc: linux-kernel@vger.kernel.org, Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , linux-s390@vger.kernel.org, Ingo Molnar , "David S. Miller" , sparclinux@vger.kernel.org, Michael Ellerman , linux-ia64@vger.kernel.org, "Rafael J. Wysocki" , Pavel Machek , Len Brown , linux-pm@vger.kernel.org, linux-acpi@vger.kernel.org, Johannes Weiner , Andrew Morton , Jonathan Corbet , linux-doc@vger.kernel.org On Thu, 31 Mar 2022 20:09:25 -0700 Randy Dunlap wrote: > @@ -5908,6 +5910,8 @@ > trace_buf_size=nn[KMG] > [FTRACE] will set tracing buffer size on each cpu. > > + trace_clock= [FTRACE] See Documentation/trace/ftrace.rst trace_clock= [FTRACE] Set the clock used for tracing events at boot up. local - Use the per CPU time stamp counter (converted into nanoseconds). Fast, but depending on the architecture, may not be in sync between CPUs. global - Event time stamps are synchronize across CPUs. May be slower than the local clock, but better for some race conditions. counter - Simple counting of events (1, 2, ..) note, some counts may be skipped due to the infrastructure grabbing the clock more than once per event. uptime - Use jiffies as the time stamp. perf - Use the same clock that perf uses. mono - Use ktime_get_mono_fast_ns() for time stamps. mono_raw - Use ktime_get_raw_fast_ns() for time stamps. boot - Use ktime_get_boot_fast_ns() for time stamps. Architectures may add more clocks. See Documentation/trace/ftrace.rst for more details. -- Steve > + > trace_event=[event-list] > [FTRACE] Set and start specified trace events in order > to facilitate early boot debugging. The event-list is a