From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
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 7605EE95A96
	for <linux-kernel@archiver.kernel.org>; Mon,  9 Oct 2023 08:14:12 +0000 (UTC)
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S234391AbjJIIOL (ORCPT <rfc822;linux-kernel@archiver.kernel.org>);
        Mon, 9 Oct 2023 04:14:11 -0400
Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49530 "EHLO
        lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S232666AbjJIIOJ (ORCPT
        <rfc822;linux-kernel@vger.kernel.org>);
        Mon, 9 Oct 2023 04:14:09 -0400
Received: from out-198.mta0.migadu.com (out-198.mta0.migadu.com [IPv6:2001:41d0:1004:224b::c6])
        by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 23C57B6
        for <linux-kernel@vger.kernel.org>; Mon,  9 Oct 2023 01:14:07 -0700 (PDT)
Message-ID: <508b33f7-3dc0-4536-21f6-4a5e7ade2b5c@linux.dev>
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1;
        t=1696839245;
        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=k+Qv4mm4LfFHvIi8wP7qIt9+6u91CDBoXpMXVpFXU9E=;
        b=reALlG5TnFKsumjcpqldLudAXAQgvY+Wrj9WQqyM/WC5hwXbSczKE0OnKNCpzd7x9qltXi
        XuhawL1h2RzrmHgPEFeArKJUMFD8DeJnj8qCDpEeialpgVCmY8GIVI7yYTDGbf6JpuJsjB
        R42q6s1hVFZ2uQMxL2EwAdno4501v6Y=
Date:   Mon, 9 Oct 2023 16:13:54 +0800
MIME-Version: 1.0
Subject: Re: [PATCH net-next v7] net/core: Introduce netdev_core_stats_inc()
Content-Language: en-US
To:     Eric Dumazet <edumazet@google.com>
Cc:     rostedt@goodmis.org, mhiramat@kernel.org, dennis@kernel.org,
        tj@kernel.org, cl@linux.com, mark.rutland@arm.com,
        davem@davemloft.net, kuba@kernel.org, pabeni@redhat.com,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        Alexander Lobakin <aleksander.lobakin@intel.com>,
        linux-trace-kernel@vger.kernel.org, linux-mm@kvack.org
References: <20231007050621.1706331-1-yajun.deng@linux.dev>
 <CANn89iL-zUw1FqjYRSC7BGB0hfQ5uKpJzUba3YFd--c=GdOoGg@mail.gmail.com>
 <917708b5-cb86-f233-e878-9233c4e6c707@linux.dev>
 <CANn89i+navyRe8-AV=ehM3qFce2hmnOEKBqvK5Xnev7KTaS5Lg@mail.gmail.com>
 <a53a3ff6-8c66-07c4-0163-e582d88843dd@linux.dev>
 <CANn89i+u5dXdYm_0_LwhXg5Nw+gHXx+nPUmbYhvT=k9P4+9JRQ@mail.gmail.com>
 <9f4fb613-d63f-9b86-fe92-11bf4dfb7275@linux.dev>
 <CANn89iK7bvQtGD=p+fHaWiiaNn=u8vWrt0YQ26pGQY=kZTdfJw@mail.gmail.com>
 <4a747fda-2bb9-4231-66d6-31306184eec2@linux.dev>
 <814b5598-5284-9558-8f56-12a6f7a67187@linux.dev>
 <CANn89iJCTgWTu0mzwj-8_-HiWm4uErY=VASDHoYaod9Nq-ayPA@mail.gmail.com>
X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers.
From:   Yajun Deng <yajun.deng@linux.dev>
In-Reply-To: <CANn89iJCTgWTu0mzwj-8_-HiWm4uErY=VASDHoYaod9Nq-ayPA@mail.gmail.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
X-Migadu-Flow: FLOW_OUT
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org


On 2023/10/9 15:53, Eric Dumazet wrote:
> On Mon, Oct 9, 2023 at 5:07 AM Yajun Deng <yajun.deng@linux.dev> wrote:
>
>> 'this_cpu_read + this_cpu_write' and 'pr_info + this_cpu_inc' will make
>> the trace work well.
>>
>> They all have 'pop' instructions in them. This may be the key to making
>> the trace work well.
>>
>> Hi all,
>>
>> I need your help on percpu and ftrace.
>>
> I do not think you made sure netdev_core_stats_inc() was never inlined.
>
> Adding more code in it is simply changing how the compiler decides to
> inline or not.


Yes, you are right. It needs to add the 'noinline' prefix. The 
disassembly code will have 'pop'

instruction.

Thanks.