From mboxrd@z Thu Jan 1 00:00:00 1970 From: rostedt@goodmis.org (Steven Rostedt) Date: Thu, 19 Mar 2015 12:40:23 -0400 Subject: [PATCH v2] ring-buffer: Replace this_cpu_*() with __this_cpu_*() In-Reply-To: References: <20150316173154.537b80ee@gandalf.local.home> <20150317081341.0f9a8b4c@gandalf.local.home> <20150317101113.32f5618a@gandalf.local.home> <20150317104038.312e73d1@gandalf.local.home> <20150317144701.GJ10068@pengutronix.de> <20150317110750.2a0e2b73@gandalf.local.home> Message-ID: <20150319124023.4c1b1094@gandalf.local.home> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, 19 Mar 2015 11:33:30 -0500 (CDT) Christoph Lameter wrote: > If you are redoing it then please get the comments a bit cleared up. The What comments should I clear up? This version did not have a comment. It just switched this_cpu_* to __this_cpu_*, and also updated a variable algorithm. -- Steve > heaviness of the fallback version of this_cpu_read/write can usually > easily be remedied by arch specific definitions. The per cpu > offset is somewhere in a register and one needs to define a macro that > creates an instruction that does a fetch from that register plus > the current offset into the area that is needed. This is similarly easy > for the write path. But then its often easier to just use the __this_cpu > instructions since preemption is often off in these code paths. > > I have had code for IA64 in the past that does this.