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[23.128.96.18]) by mx.google.com with ESMTP id sb9si1752242ejb.54.2020.09.23.23.40.12; Wed, 23 Sep 2020 23:40:35 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=Ulx1bpyG; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727001AbgIXGjE (ORCPT + 99 others); Thu, 24 Sep 2020 02:39:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41472 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726721AbgIXGjD (ORCPT ); Thu, 24 Sep 2020 02:39:03 -0400 Received: from mail-pj1-x1041.google.com (mail-pj1-x1041.google.com [IPv6:2607:f8b0:4864:20::1041]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0CCAEC0613CE for ; Wed, 23 Sep 2020 23:39:03 -0700 (PDT) Received: by mail-pj1-x1041.google.com with SMTP id mn7so1071998pjb.5 for ; Wed, 23 Sep 2020 23:39:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=0XdoGsthdP0st5oc3oiLDJoWjs7OJH+8MYDHvoMVNdQ=; b=Ulx1bpyG87cjZx3cGY6T63diD/f6gR/G2OLQVPojfDalMYXegtyu4DsgqrlBb5xeLQ 8f+8vMhG5/anIvMxso1kCcHz6J4kyTw1fe2FxSwJCi8xjkn6ozkUh6N9LeUtS4JWKjXR 18HeH5xr84wP+ObKWF48RQSr3lpxFXk4Zv01VmzdQG6X45VwlCh10b9i3o4DevTMk1IJ g8Rw0H6JaFaYSrXmFfzqZGEmX70DIkWuTPCOoF9BedJdMbqhzLFvfIQaKr0iGEKeABRl 4Z7zPVJMs2lYipVoqBpiQRRWKVEP8Mi0U7k/h02ORuvsVrEtqSx8QCxdrNi5iHTHFtY9 05VQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=0XdoGsthdP0st5oc3oiLDJoWjs7OJH+8MYDHvoMVNdQ=; b=mWL2AiBI3G2ObZsuNnCl68BK3Z0+FpYszCaiJURs+Hvlzw0nCpMX00zLkKN2EexZgJ qSTgczLNIXGp8zZ97UpcOO8vA6/zrgv/oFlVT/Iq2EJJ6eN3r31434dPX6B3Xm8UH7MO hPd9W0/ffi5NRdwE673heeKUWH2CGu4WWp4SLTHV4DLJrxYRyzVEat/dh6DeCKm7H61J 365r18vxj97uh6mxxRUN6Aw9tT+GwvTo/6rkA0IYf61cqJxLiza3FoC32MgXOQCdoFiy yUQxYDhuc6Al5KnpZzm6IdVVKJeNenkA5v/SeFogH2giT+A/OGAHQ8N4BTMqCbB/9qDH 0fjg== X-Gm-Message-State: AOAM532Vhmv9xjJKhb1qOPb64zKDy6WAkEIbixKtGGKQKyLFrV5bJsfN e78ZZ051URBTbKY/Mcr6/lM= X-Received: by 2002:a17:90a:d493:: with SMTP id s19mr2617266pju.91.1600929542518; Wed, 23 Sep 2020 23:39:02 -0700 (PDT) Received: from localhost ([2409:10:2e40:5100:6e29:95ff:fe2d:8f34]) by smtp.gmail.com with ESMTPSA id r6sm1586305pfq.11.2020.09.23.23.39.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 23 Sep 2020 23:39:01 -0700 (PDT) Date: Thu, 24 Sep 2020 15:38:59 +0900 From: Sergey Senozhatsky To: Prasad Sodagudi Cc: rostedt@goodmis.org, pmladek@suse.com, sergey.senozhatsky@gmail.com, gregkh@linuxfoundation.org, tglx@linutronix.de, linux-kernel@vger.kernel.org, tkjos@google.com, Mohammed Khajapasha Subject: Re: [PATCH 2/2] printk: Make the console flush configurable in hotplug path Message-ID: <20200924063859.GA763318@jagdpanzerIV.localdomain> References: <1600906112-126722-1-git-send-email-psodagud@codeaurora.org> <1600906112-126722-2-git-send-email-psodagud@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1600906112-126722-2-git-send-email-psodagud@codeaurora.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On (20/09/23 17:08), Prasad Sodagudi wrote: > From: Mohammed Khajapasha > > The thread which initiates the hot plug can get scheduled > out, while trying to acquire the console lock, > thus increasing the hot plug latency. This option > allows to selectively disable the console flush and > in turn reduce the hot plug latency. It can schedule out or get preempted pretty much anywhere at any time. printk->console_lock is not special in this regard. What am I missing? -ss