From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754000AbeEON7B (ORCPT ); Tue, 15 May 2018 09:59:01 -0400 Received: from mail.kernel.org ([198.145.29.99]:44460 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753984AbeEON7A (ORCPT ); Tue, 15 May 2018 09:59:00 -0400 Date: Tue, 15 May 2018 15:58:57 +0200 From: Frederic Weisbecker To: Ingo Molnar Cc: Peter Zijlstra , LKML , Jiri Olsa , Namhyung Kim , Linus Torvalds , Yoshinori Sato , Benjamin Herrenschmidt , Catalin Marinas , Chris Zankel , Paul Mackerras , Thomas Gleixner , Will Deacon , Michael Ellerman , Rich Felker , Mark Rutland , Alexander Shishkin , Andy Lutomirski , Arnaldo Carvalho de Melo , Max Filippov Subject: Re: [PATCH 8/9] perf/breakpoint: Split breakpoint "check" and "commit" Message-ID: <20180515135856.GC24389@lerouge> References: <1525634395-23380-1-git-send-email-frederic@kernel.org> <1525634395-23380-9-git-send-email-frederic@kernel.org> <20180509091703.GH12217@hirez.programming.kicks-ass.net> <20180515065747.GA626@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180515065747.GA626@gmail.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 15, 2018 at 08:57:47AM +0200, Ingo Molnar wrote: > > * Peter Zijlstra wrote: > > > On Sun, May 06, 2018 at 09:19:54PM +0200, Frederic Weisbecker wrote: > > > arch/arm/include/asm/hw_breakpoint.h | 5 ++++- > > > arch/arm/kernel/hw_breakpoint.c | 22 +++------------------- > > > arch/arm64/include/asm/hw_breakpoint.h | 5 ++++- > > > arch/arm64/kernel/hw_breakpoint.c | 22 +++------------------- > > > arch/powerpc/include/asm/hw_breakpoint.h | 5 ++++- > > > arch/powerpc/kernel/hw_breakpoint.c | 22 +++------------------- > > > arch/sh/include/asm/hw_breakpoint.h | 5 ++++- > > > arch/sh/kernel/hw_breakpoint.c | 22 +++------------------- > > > arch/x86/include/asm/hw_breakpoint.h | 5 ++++- > > > arch/x86/kernel/hw_breakpoint.c | 23 +++-------------------- > > > arch/xtensa/include/asm/hw_breakpoint.h | 5 ++++- > > > arch/xtensa/kernel/hw_breakpoint.c | 22 +++------------------- > > > > Because of those ^, > > > > > kernel/events/hw_breakpoint.c | 11 ++++++----- > > > > would it not make sense to have a prelimenary patch doing something > > like: > > > > __weak int hw_breakpoint_arch_check(struct perf_event *bp) > > { > > return arch_validate_hwbkpt_settings(bp); > > } > > > > __weak void hw_breakpoint_arch_commit(struct perf_event *bp) > > { > > } > > > > combined with this bit: > > > > > diff --git a/kernel/events/hw_breakpoint.c b/kernel/events/hw_breakpoint.c > > > index 6e28d28..6896ceeb 100644 > > > --- a/kernel/events/hw_breakpoint.c > > > +++ b/kernel/events/hw_breakpoint.c > > > @@ -402,11 +402,12 @@ int dbg_release_bp_slot(struct perf_event *bp) > > > > > > static int validate_hw_breakpoint(struct perf_event *bp) > > > { > > > - int ret; > > > + int err; > > > > > > - ret = arch_validate_hwbkpt_settings(bp); > > > - if (ret) > > > - return ret; > > > + err = hw_breakpoint_arch_check(bp, &bp->attr); > > > + if (err) > > > + return err; > > > + hw_breakpoint_arch_commit(bp); > > > > > > if (arch_check_bp_in_kernelspace(bp)) { > > > if (bp->attr.exclude_kernel) > > > > And then convert the archs over one by one, and at the end remove the > > weak thingies entirely? > > Makes sense. > > The rest looks good to me - Frederic, once you implement Peter's uggestion I > suspect this series can be applied. Right, I'll try to do a smoother transition as in Peterz suggestion. I'm just going to pass around the struct arch_hw_breakpoint to avoid code duplication in check and commit. The end result may look like: struct arch_hw_breakpoint hw; int err; err = hw_breakpoint_arch_parse(bp, attr, &hw); if (err) return err; ..... bp->hw.info = hw;