From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 89410C433F5 for ; Tue, 19 Apr 2022 16:31:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1354634AbiDSQdo (ORCPT ); Tue, 19 Apr 2022 12:33:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46680 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229538AbiDSQdl (ORCPT ); Tue, 19 Apr 2022 12:33:41 -0400 Received: from mail-yb1-f178.google.com (mail-yb1-f178.google.com [209.85.219.178]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 67A5B167E5; Tue, 19 Apr 2022 09:30:57 -0700 (PDT) Received: by mail-yb1-f178.google.com with SMTP id i20so31988704ybj.7; Tue, 19 Apr 2022 09:30:57 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=1swu2cTkh+aC67hs8/dbpRCHUF/l5DGtGfoyG/d6XKk=; b=J1/ruRcPMJaZq7qjrrx0TXkP7nD6MSIfWnWk/OX7rYokdQP1KbskYA6fUlCZvLuSFn g8uX9SA372G0zPzbIjeC09mCtoKuZs25RzV9vnfZ0oZ/Jdzkf8kftk3/lwdpyJK6PcqR 6EyuXx2Rl+iyHeD5syP8HVXch2F0mjzBt61d5L92QNS4nfooxLW+Rayw5VObfyZ3dIOr cUzikfsP2hXeHmEbH/8AiaEvbdqDHH3hIuyYLrImNgzx4xOM+2g5zLhU7fQN3GeRSEf6 dVzVMf740SlVQuXgLcyRldJ7VXU8zR2IGdx/DSH5Z57QJmMIaplMBfJ6wNpP71kXh2kY 0ang== X-Gm-Message-State: AOAM532Jv5Yd0NMFwGFd1HYvdjFkBWCR8sNAdcXmDnlY2zMCYLaFYTmD UmAh9CSZWyqlp9bcaPEaWJug3tFwHILyI0wrpho= X-Google-Smtp-Source: ABdhPJwgJQoyFgoJ4viOOB7zae8VQfrZU3484x23p0NkjJKHc4tOrAbCdxVE+zqLVq/2BAz68JJcq87Hc3UBhR5fH7w= X-Received: by 2002:a05:6902:187:b0:63d:9c95:edca with SMTP id t7-20020a056902018700b0063d9c95edcamr15432354ybh.81.1650385856684; Tue, 19 Apr 2022 09:30:56 -0700 (PDT) MIME-Version: 1.0 References: <20220415133356.179706384@linutronix.de> <20220415161206.817702355@linutronix.de> In-Reply-To: <20220415161206.817702355@linutronix.de> From: "Rafael J. Wysocki" Date: Tue, 19 Apr 2022 18:30:45 +0200 Message-ID: Subject: Re: [patch 08/10] x86/aperfmperf: Store aperf/mperf data for cpu frequency reads To: Thomas Gleixner Cc: LKML , "the arch/x86 maintainers" , "Rafael J. Wysocki" , Linux PM , Eric Dumazet , "Paul E. McKenney" Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Apr 15, 2022 at 9:20 PM Thomas Gleixner wrote: > > Now that the MSR readout is unconditional, store the results in the per CPU > data structure along with a jiffies timestamp for the CPU frequency readout > code. > > Signed-off-by: Thomas Gleixner Acked-by: Rafael J. Wysocki > --- > arch/x86/kernel/cpu/aperfmperf.c | 14 +++++++++++++- > 1 file changed, 13 insertions(+), 1 deletion(-) > > --- a/arch/x86/kernel/cpu/aperfmperf.c > +++ b/arch/x86/kernel/cpu/aperfmperf.c > @@ -24,11 +24,17 @@ > #include "cpu.h" > > struct aperfmperf { > + seqcount_t seq; > + unsigned long last_update; > + u64 acnt; > + u64 mcnt; > u64 aperf; > u64 mperf; > }; > > -static DEFINE_PER_CPU_SHARED_ALIGNED(struct aperfmperf, cpu_samples); > +static DEFINE_PER_CPU_SHARED_ALIGNED(struct aperfmperf, cpu_samples) = { > + .seq = SEQCNT_ZERO(cpu_samples.seq) > +}; > > struct aperfmperf_sample { > unsigned int khz; > @@ -515,6 +521,12 @@ void arch_scale_freq_tick(void) > s->aperf = aperf; > s->mperf = mperf; > > + raw_write_seqcount_begin(&s->seq); > + s->last_update = jiffies; > + s->acnt = acnt; > + s->mcnt = mcnt; > + raw_write_seqcount_end(&s->seq); > + > scale_freq_tick(acnt, mcnt); > } > >