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 9DE42C25B6F for ; Thu, 26 Oct 2023 08:53:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229642AbjJZIxh (ORCPT ); Thu, 26 Oct 2023 04:53:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33448 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344757AbjJZIxa (ORCPT ); Thu, 26 Oct 2023 04:53:30 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 21DD410E3; Thu, 26 Oct 2023 01:53:27 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 2F3592F4; Thu, 26 Oct 2023 01:54:08 -0700 (PDT) Received: from bogus (e103737-lin.cambridge.arm.com [10.1.197.49]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 5154F3F762; Thu, 26 Oct 2023 01:53:24 -0700 (PDT) Date: Thu, 26 Oct 2023 09:53:21 +0100 From: Sudeep Holla To: Zeng Heng Cc: , , , Sudeep Holla , , , , , , , , , , , , , , Subject: Re: [PATCH 2/3] cpufreq: CPPC: Keep the target core awake when reading its cpufreq rate Message-ID: References: <20231025093847.3740104-1-zengheng4@huawei.com> <20231025093847.3740104-3-zengheng4@huawei.com> <20231025111301.ng5eaeaixfs3jjpg@bogus> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org On Thu, Oct 26, 2023 at 10:24:54AM +0800, Zeng Heng wrote: > > 在 2023/10/25 19:13, Sudeep Holla 写道: > > On Wed, Oct 25, 2023 at 05:38:46PM +0800, Zeng Heng wrote: > > > As ARM AMU's document says, all counters are subject to any changes > > > in clock frequency, including clock stopping caused by the WFI and WFE > > > instructions. > > > > > > Therefore, using smp_call_on_cpu() to trigger target CPU to > > > read self's AMU counters, which ensures the counters are working > > > properly while cstate feature is enabled. > > > > > > Reported-by: Sumit Gupta > > > Link: https://lore.kernel.org/all/20230418113459.12860-7-sumitg@nvidia.com/ > > > Signed-off-by: Zeng Heng > > > --- > > > drivers/cpufreq/cppc_cpufreq.c | 39 ++++++++++++++++++++++++++-------- > > > 1 file changed, 30 insertions(+), 9 deletions(-) > > > > > > diff --git a/drivers/cpufreq/cppc_cpufreq.c b/drivers/cpufreq/cppc_cpufreq.c > > > index fe08ca419b3d..321a9dc9484d 100644 > > > --- a/drivers/cpufreq/cppc_cpufreq.c > > > +++ b/drivers/cpufreq/cppc_cpufreq.c > > [...] > > > > > @@ -850,18 +871,18 @@ static unsigned int cppc_cpufreq_get_rate(unsigned int cpu) > > > cpufreq_cpu_put(policy); > > > - ret = cppc_get_perf_ctrs(cpu, &fb_ctrs_t0); > > > - if (ret) > > > - return 0; > > > - > > > - udelay(2); /* 2usec delay between sampling */ > > > + if (cpu_has_amu_feat(cpu)) > > Have you compiled this on x86 ? Even if you have somehow managed to, > > this is not the right place to check the presence of AMU feature on > > the CPU. > > If AMU registers are used in CPPC, they must be using FFH GAS, in which > > case the interpretation of FFH is architecture dependent code. > > According to drivers/cpufreq/Makefile, cppc_cpufreq.c is only compiled with > ARM architecture. > Well that's true but this change doesn't belong to cppc_cpufreq.c, it must be part of drivers/acpi/cppc_acpi.c IMO and sorry I assumed that without explicitly mentioning that here. > But here, I would change cpu_has_amu_feat() with cpc_ffh_supported(), which > belongs to FFH APIs. > It is not like that. cppc_acpi.c will know the GAS is FFH based so no need to check anything there. I see counters_read_on_cpu() called from cpc_ffh_read() already takes care of reading the AMUs on the right CPU. What exactly is the issue you are seeing ? I don't if this change is needed at all. -- Regards, Sudeep 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D3D48C25B70 for ; Thu, 26 Oct 2023 08:54:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=Gx1BE7Yfd1KCA71VY2t9acQ7QKoXn4yZyDuhq39rSII=; b=GLm/V+ZO2nu+g3 sObkqbWk+uN7RIAl2fsK+ODEua5nQLyeMUmnoG89o1uncnaekwfEuT8zjMxr6ahloX+rcNEKFYcQ5 xjHkAkADCqznRkvKyr20E6VC7k5WNb5DBlg4Fj6GUM/7dD8Q2RPGQMG34E5Mr62BXFrkEw9VtP25T HUcIEbpZAR0hfyT6Cw+dA0mxEFvCOuiwgsJwHPhThu7jz0Z0yMHWcVWkr6ve9GSnVfTDu0DidKi7K NenojUmKXsJJ5jMepMAk55rpm4y8YK7bd4AzNotUXtFIvW63iVXPxvcp7tPnsG5MX0TUvpX/IkkSP anljaP3caibZ0OlvwYZA==; 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charset="utf-8" Content-Transfer-Encoding: base64 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org T24gVGh1LCBPY3QgMjYsIDIwMjMgYXQgMTA6MjQ6NTRBTSArMDgwMCwgWmVuZyBIZW5nIHdyb3Rl Ogo+IAo+IOWcqCAyMDIzLzEwLzI1IDE5OjEzLCBTdWRlZXAgSG9sbGEg5YaZ6YGTOgo+ID4gT24g V2VkLCBPY3QgMjUsIDIwMjMgYXQgMDU6Mzg6NDZQTSArMDgwMCwgWmVuZyBIZW5nIHdyb3RlOgo+ ID4gPiBBcyBBUk0gQU1VJ3MgZG9jdW1lbnQgc2F5cywgYWxsIGNvdW50ZXJzIGFyZSBzdWJqZWN0 IHRvIGFueSBjaGFuZ2VzCj4gPiA+IGluIGNsb2NrIGZyZXF1ZW5jeSwgaW5jbHVkaW5nIGNsb2Nr IHN0b3BwaW5nIGNhdXNlZCBieSB0aGUgV0ZJIGFuZCBXRkUKPiA+ID4gaW5zdHJ1Y3Rpb25zLgo+ ID4gPiAKPiA+ID4gVGhlcmVmb3JlLCB1c2luZyBzbXBfY2FsbF9vbl9jcHUoKSB0byB0cmlnZ2Vy IHRhcmdldCBDUFUgdG8KPiA+ID4gcmVhZCBzZWxmJ3MgQU1VIGNvdW50ZXJzLCB3aGljaCBlbnN1 cmVzIHRoZSBjb3VudGVycyBhcmUgd29ya2luZwo+ID4gPiBwcm9wZXJseSB3aGlsZSBjc3RhdGUg ZmVhdHVyZSBpcyBlbmFibGVkLgo+ID4gPiAKPiA+ID4gUmVwb3J0ZWQtYnk6IFN1bWl0IEd1cHRh IDxzdW1pdGdAbnZpZGlhLmNvbT4KPiA+ID4gTGluazogaHR0cHM6Ly9sb3JlLmtlcm5lbC5vcmcv YWxsLzIwMjMwNDE4MTEzNDU5LjEyODYwLTctc3VtaXRnQG52aWRpYS5jb20vCj4gPiA+IFNpZ25l ZC1vZmYtYnk6IFplbmcgSGVuZyA8emVuZ2hlbmc0QGh1YXdlaS5jb20+Cj4gPiA+IC0tLQo+ID4g PiAgIGRyaXZlcnMvY3B1ZnJlcS9jcHBjX2NwdWZyZXEuYyB8IDM5ICsrKysrKysrKysrKysrKysr KysrKysrKysrLS0tLS0tLS0KPiA+ID4gICAxIGZpbGUgY2hhbmdlZCwgMzAgaW5zZXJ0aW9ucygr KSwgOSBkZWxldGlvbnMoLSkKPiA+ID4gCj4gPiA+IGRpZmYgLS1naXQgYS9kcml2ZXJzL2NwdWZy ZXEvY3BwY19jcHVmcmVxLmMgYi9kcml2ZXJzL2NwdWZyZXEvY3BwY19jcHVmcmVxLmMKPiA+ID4g aW5kZXggZmUwOGNhNDE5YjNkLi4zMjFhOWRjOTQ4NGQgMTAwNjQ0Cj4gPiA+IC0tLSBhL2RyaXZl cnMvY3B1ZnJlcS9jcHBjX2NwdWZyZXEuYwo+ID4gPiArKysgYi9kcml2ZXJzL2NwdWZyZXEvY3Bw Y19jcHVmcmVxLmMKPiA+IFsuLi5dCj4gPiAKPiA+ID4gQEAgLTg1MCwxOCArODcxLDE4IEBAIHN0 YXRpYyB1bnNpZ25lZCBpbnQgY3BwY19jcHVmcmVxX2dldF9yYXRlKHVuc2lnbmVkIGludCBjcHUp Cj4gPiA+ICAgCWNwdWZyZXFfY3B1X3B1dChwb2xpY3kpOwo+ID4gPiAtCXJldCA9IGNwcGNfZ2V0 X3BlcmZfY3RycyhjcHUsICZmYl9jdHJzX3QwKTsKPiA+ID4gLQlpZiAocmV0KQo+ID4gPiAtCQly ZXR1cm4gMDsKPiA+ID4gLQo+ID4gPiAtCXVkZWxheSgyKTsgLyogMnVzZWMgZGVsYXkgYmV0d2Vl biBzYW1wbGluZyAqLwo+ID4gPiArCWlmIChjcHVfaGFzX2FtdV9mZWF0KGNwdSkpCj4gPiBIYXZl IHlvdSBjb21waWxlZCB0aGlzIG9uIHg4NiA/IEV2ZW4gaWYgeW91IGhhdmUgc29tZWhvdyBtYW5h Z2VkIHRvLAo+ID4gdGhpcyBpcyBub3QgdGhlIHJpZ2h0IHBsYWNlIHRvIGNoZWNrIHRoZSBwcmVz ZW5jZSBvZiBBTVUgZmVhdHVyZSBvbgo+ID4gdGhlIENQVS4KPiA+IElmIEFNVSByZWdpc3RlcnMg YXJlIHVzZWQgaW4gQ1BQQywgdGhleSBtdXN0IGJlIHVzaW5nIEZGSCBHQVMsIGluIHdoaWNoCj4g PiBjYXNlIHRoZSBpbnRlcnByZXRhdGlvbiBvZiBGRkggaXMgYXJjaGl0ZWN0dXJlIGRlcGVuZGVu dCBjb2RlLgo+Cj4gQWNjb3JkaW5nIHRvIGRyaXZlcnMvY3B1ZnJlcS9NYWtlZmlsZSwgY3BwY19j cHVmcmVxLmMgaXMgb25seSBjb21waWxlZCB3aXRoCj4gQVJNIGFyY2hpdGVjdHVyZS4KPgoKV2Vs bCB0aGF0J3MgdHJ1ZSBidXQgdGhpcyBjaGFuZ2UgZG9lc24ndCBiZWxvbmcgdG8gY3BwY19jcHVm cmVxLmMsIGl0IG11c3QKYmUgcGFydCBvZiBkcml2ZXJzL2FjcGkvY3BwY19hY3BpLmMgSU1PIGFu ZCBzb3JyeSBJIGFzc3VtZWQgdGhhdCB3aXRob3V0CmV4cGxpY2l0bHkgbWVudGlvbmluZyB0aGF0 IGhlcmUuCgo+IEJ1dCBoZXJlLCBJIHdvdWxkIGNoYW5nZSBjcHVfaGFzX2FtdV9mZWF0KCkgd2l0 aCBjcGNfZmZoX3N1cHBvcnRlZCgpLCB3aGljaAo+IGJlbG9uZ3MgdG8gRkZIIEFQSXMuCj4KCkl0 IGlzIG5vdCBsaWtlIHRoYXQuIGNwcGNfYWNwaS5jIHdpbGwga25vdyB0aGUgR0FTIGlzIEZGSCBi YXNlZCBzbyBubyBuZWVkIHRvCmNoZWNrIGFueXRoaW5nIHRoZXJlLiBJIHNlZSBjb3VudGVyc19y ZWFkX29uX2NwdSgpIGNhbGxlZCBmcm9tIGNwY19mZmhfcmVhZCgpCmFscmVhZHkgdGFrZXMgY2Fy ZSBvZiByZWFkaW5nIHRoZSBBTVVzIG9uIHRoZSByaWdodCBDUFUuIFdoYXQgZXhhY3RseSBpcwp0 aGUgaXNzdWUgeW91IGFyZSBzZWVpbmcgPyBJIGRvbid0IGlmIHRoaXMgY2hhbmdlIGlzIG5lZWRl ZCBhdCBhbGwuCgotLQpSZWdhcmRzLApTdWRlZXAKCl9fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fCmxpbnV4LWFybS1rZXJuZWwgbWFpbGluZyBsaXN0CmxpbnV4 LWFybS1rZXJuZWxAbGlzdHMuaW5mcmFkZWFkLm9yZwpodHRwOi8vbGlzdHMuaW5mcmFkZWFkLm9y Zy9tYWlsbWFuL2xpc3RpbmZvL2xpbnV4LWFybS1rZXJuZWwK