From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay8-d.mail.gandi.net (relay8-d.mail.gandi.net [217.70.183.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C87EE15D5C3; Wed, 23 Oct 2024 10:30:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.70.183.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729679420; cv=none; b=FkVLOStU+/ij/G0XU6XFxzX8DO6Lci2XJjBEKoQzPQgGUBYdH3O+pk9pRAknPax+JKVHR6NsGkOVU5m12XJhRI39wRkUsq6maZfrkxLSeaYdhEH1MKhE8MpGgpV3EydWkNV6ZFbW5UUS2RxKNVFi/yj1KV6/bkLuRL6+3EKJOe0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729679420; c=relaxed/simple; bh=dOCQHfeOAkgXh2JrunAu9gHeLhGEIKF9LRTDykv07m4=; h=Message-ID:Date:MIME-Version:Subject:From:To:Cc:References: In-Reply-To:Content-Type; b=mxM6X5l73qhSW5Ex4pRZYUDWdV3c4ZQzeUmavVcDt00LOoISZXf2/OakbdoVxenK2Um0RgPj/QHvSHp3QhXLuAlsNMsyGWvhnTIKKevXyl8Ovmlt1cDWDbrYfJ5mFDt/aleUVsyzLTZN6x9wgHKPTSTSMKPjdsPE1ARJQQ6uz90= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=yoseli.org; spf=none smtp.mailfrom=yoseli.org; dkim=pass (2048-bit key) header.d=yoseli.org header.i=@yoseli.org header.b=l+5jMATm; arc=none smtp.client-ip=217.70.183.201 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=yoseli.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=yoseli.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=yoseli.org header.i=@yoseli.org header.b="l+5jMATm" Received: by mail.gandi.net (Postfix) with ESMTPSA id B45EA1BF212; Wed, 23 Oct 2024 10:30:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yoseli.org; s=gm1; t=1729679417; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=CMFTUHAj70OERwwWzi9yxbynPpD8S8y4BGK+6PB4HEU=; b=l+5jMATm4m4Ezx0EVbIVhHbJWaDtJHmKEV9YtgZCabCwKgTm1DP4ZXx7hKS2HIvUvF+NIn r1ckqEHVCbSrk2coJVjwDgUBxAiCPBL+THYam6OmnqVfHJnwB/So0GWfN0HEw7wXTeyht5 NlGRZrBu90OOuZamArfvRauuYqulHh8EPZgQyjrbUA2BCHUrKSrrJ/gsoBau5DUJV3tekP 1Gi8lu1vDA4+ftFJerue03hDe5pBLS87lYC3iYqR/KqjkT+HdmKIyw0HVdDFXuLehnYX9m TmRGvWttQoEvHg6eK/nwnviHjaecTr584Yw3XR+i/f5NdIWg0QGoB3kuBo0ZZg== Message-ID: Date: Wed, 23 Oct 2024 12:30:16 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH RFC 1/2] m68k: Add tracirqs From: Jean-Michel Hautbois To: Geert Uytterhoeven Cc: Steven Rostedt , linux-m68k@lists.linux-m68k.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org References: <20241021-add-m68k-tracing-support-v1-0-0883d704525b@yoseli.org> <20241021-add-m68k-tracing-support-v1-1-0883d704525b@yoseli.org> <20241022012809.1ef083cd@rorschach.local.home> <075d6720-a690-437c-a10f-e2746651e2a8@yoseli.org> <20241022043037.13efb239@rorschach.local.home> <2c79be22-1157-41e4-9f3a-53443112ca9a@yoseli.org> <20241023044711.3eb838fe@rorschach.local.home> <262d7758-c752-49f6-87ef-4f75d681a919@yoseli.org> Content-Language: en-US In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-GND-Sasl: jeanmichel.hautbois@yoseli.org Hi Geert, all, On 23/10/2024 11:31, Jean-Michel Hautbois wrote: > Hi Geert, > > On 23/10/2024 11:13, Geert Uytterhoeven wrote: >> Hi Jean-Michel, >> >> On Wed, Oct 23, 2024 at 11:07 AM Jean-Michel Hautbois >> wrote: >>> On 23/10/2024 10:47, Steven Rostedt wrote: >>>> On Tue, 22 Oct 2024 11:21:34 +0200 >>>> Jean-Michel Hautbois wrote: >>>>> I was not really expecting you to review the m68k one no :-). >>>>> I think I have other issues which might have impact on ftrace too. >>>>> For instance, when I launch cyclictest I have a warning about >>>>> HRTIMERS: >>>>> # cyclictest -p 99 >>>>> WARN: stat /dev/cpu_dma_latency failed: No such file or directory >>>>> WARN: High resolution timers not available >>>>> policy: fifo: loadavg: 1.21 0.40 0.14 1/122 245 >>>>> >>>>> T: 0 (  245) P:99 I:1000 C:  11203 Min:     92 Act:  623 Avg:  775 >>>>> Max: >>>>>      3516 >>>>> >>>>> The latencies are quite high... >>>> >>>> Yes, if you don't have high resolution timers, the latency will be >>>> high. >>> >>> According to my config, I should have those: >>> CONFIG_HIGH_RES_TIMERS=y >> >> Does your hardware have a high resolution timer, and do you have >> a driver for it? >> >> $ git grep hrtimer -- arch/m68k/ >> $ >> > > No, there is nothing with hrtimer. But, the architecture has four dma > timers, with a 8ns resolution at 125MHz says the documentation. I will > try to find a way to implement the missing part. > I gave it a hacky try. And it seems to be *a lot* better: # cyclictest -p 99 -l 10000 WARN: stat /dev/cpu_dma_latency failed: No such file or directory policy: fifo: loadavg: 1.18 0.71 0.33 1/122 258 T: 0 ( 258) P:99 I:1000 C: 10000 Min: 118 Act: 1104 Avg: 418 Max: 1858 I will try to clean it a bit for another patch set :-). Thanks, JM