From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ingo Molnar Subject: Re: [PATCH v2 16/17] x86/insn: remove pcommit Date: Sat, 23 Jul 2016 09:49:06 +0200 Message-ID: <20160723074906.GA21154@gmail.com> References: <146812106839.32932.2870621200867047059.stgit@dwillia2-desk3.amr.corp.intel.com> <146812115425.32932.3314855641604340233.stgit@dwillia2-desk3.amr.corp.intel.com> <20160712145757.GV30909@twins.programming.kicks-ass.net> <20160722165246.GA24884@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-nvdimm-bounces-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org Sender: "Linux-nvdimm" To: Dan Williams Cc: Xiao Guangrong , Peter Zijlstra , linux-nvdimm , X86 ML , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Arnaldo Carvalho de Melo , Adrian Hunter , Linux ACPI , Alexander Shishkin , Ingo Molnar , Andy Lutomirski , Josh Poimboeuf , linux-fsdevel , Thomas Gleixner , Borislav Petkov , "H. Peter Anvin" , Christoph Hellwig List-Id: linux-acpi@vger.kernel.org * Dan Williams wrote: > On Fri, Jul 22, 2016 at 9:52 AM, Ingo Molnar wrote: > > > > * Dan Williams wrote: > > > >> On Tue, Jul 12, 2016 at 3:12 PM, Dan Williams wrote: > >> > On Tue, Jul 12, 2016 at 7:57 AM, Peter Zijlstra wrote: > >> >> On Sat, Jul 09, 2016 at 08:25:54PM -0700, Dan Williams wrote: > >> >>> The pcommit instruction is being deprecated in favor of either ADR > >> >>> (asynchronous DRAM refresh: flush-on-power-fail) at the platform level, or > >> >>> posted-write-queue flush addresses as defined by the ACPI 6.x NFIT (NVDIMM > >> >>> Firmware Interface Table). > >> >> > >> >>> arch/x86/include/asm/cpufeatures.h | 1 > >> >>> arch/x86/include/asm/special_insns.h | 46 -------------------- > >> >>> arch/x86/lib/x86-opcode-map.txt | 2 - > >> >>> tools/objtool/arch/x86/insn/x86-opcode-map.txt | 2 - > >> >>> tools/perf/arch/x86/tests/insn-x86-dat-32.c | 2 - > >> >>> tools/perf/arch/x86/tests/insn-x86-dat-64.c | 2 - > >> >>> tools/perf/arch/x86/tests/insn-x86-dat-src.c | 4 -- > >> >> > >> >> Just deprecated, or is it completely eradicated, removed from history, > >> >> will never ever happen and we'll reissue the opcode for something else? > >> >> > >> >> Because if its only deprecated then removing it from the instruction > >> >> decoders seems wrong, old binaries might still contain the opcode. > >> > > >> > Eradicated. > >> > > >> > "The new instructions like CLWB and CLFLUSHOPT will be rolled into the > >> > SDM but PCOMMIT will be removed from the Extensions doc and not rolled > >> > into the SDM." [1] > >> > > >> > Existing binaries are already gating their usage on the presence of > >> > the cpu id flag, that flag and the instruction opcode are reserved > >> > going forward. > >> > > >> > [1]: https://lists.01.org/pipermail/linux-nvdimm/2016-June/005923.html > >> > >> x86 maintainers, I have the other patches in this series queued in -next. Please > >> ack this one and I'll add it for v4.8-rc1, or otherwise let me know how you want > >> to handle this patch. > > > > Since it's just a removal AFAICS that the rest of your series should not depend > > on, can you submit it to the x86 tree? > > This patch depends on the previous patches in the series removing > calls to pcommit_sfence(). Ok, and the patch looks harmless: Acked-by: Ingo Molnar Thanks, Ingo