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 X-Spam-Level: X-Spam-Status: No, score=0.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,GUARANTEED_100_PERCENT, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C435FC46475 for ; Thu, 25 Oct 2018 06:48:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 696C32082D for ; Thu, 25 Oct 2018 06:48:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="jaNLW3R1" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 696C32082D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726800AbeJYPTc (ORCPT ); Thu, 25 Oct 2018 11:19:32 -0400 Received: from mail-pf1-f194.google.com ([209.85.210.194]:41573 "EHLO mail-pf1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726433AbeJYPTc (ORCPT ); Thu, 25 Oct 2018 11:19:32 -0400 Received: by mail-pf1-f194.google.com with SMTP id a19-v6so3695606pfo.8; Wed, 24 Oct 2018 23:48:10 -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:user-agent; bh=mMryRUaVaiAa++Iu7e/9dL7uBfQZUysOLKyMn5oKodI=; b=jaNLW3R1JSUcTXcxp37rGha31ZJQWIA6s2Hx+OgTI8yLPueGq+DtZoHHPyI24NJ6vU 02wXpjt5M6/NGQTLX0vIEgd3WWdzr3oNX/YtCFwcyTSCxffh9kvFTQaTMqJCThQtmFaw 83uPfZx9wtHtIk87AOU+Y2slrSNHEjWo9Nl5188KGJIvFAnpXUDCE8etrKrlH0L0334Y 45I3kDI4mpk28avxAIHFR1Z4mjqOEZZfL/y9vM/xa62nNJPRaZg3GcN21oytut5xWvmI zjDCXFdBPsBzL2Z8nvqB0XU/3fRNMGdGj7IO/8NT56i9jSJXvfCQ0AXOvqN6X9TO9wHY wT5w== 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:user-agent; bh=mMryRUaVaiAa++Iu7e/9dL7uBfQZUysOLKyMn5oKodI=; b=Rmqc7TEotNRkagxfhlREr/Q5mTCbEihqx02BUJxJFsS3DOZiBduAPnI1oHUkS+COPW D0Bd4GFS0bAMZqsrb4nvd8kvC8IM0IGeSMq3VZ/tRnR7Q2lpkxqDDRwp9Hcf/Gd8mx9j RG9iUC2+cS73ALE9GyH2DW96vwOAdBuOq1XsbWqS9/yhmnDBmjSNmN73+qf05JX9pojf +X0pF6VAyeGkxpGxL09IZ3/B4/LESSqY9TNBUmRF2wrkr4kifjUNc4S2jckdfqTW4e3n GoXGw9gbwwe6Jo2lMchjtMfYad6gDTqIECGcN7kXeQFzTRg1sclLR5MmjvC5GfOlTezG MgmQ== X-Gm-Message-State: AGRZ1gKTeEvOcdlTHTnABI2cdRkpY/0BlAkYf9SKnmXuRpeAP07TlB3s 83PEptdkjwZO81GbMnCmpJQ= X-Google-Smtp-Source: AJdET5dkEicWHmKS8IJfkyZhWp3recDfZ6cJTNaR5m5H0YxNv6caNVWbn2FN/9qoBor9UIweEknJww== X-Received: by 2002:a63:3c19:: with SMTP id j25mr334771pga.286.1540450089892; Wed, 24 Oct 2018 23:48:09 -0700 (PDT) Received: from localhost ([175.223.22.26]) by smtp.gmail.com with ESMTPSA id v26-v6sm8543127pfg.43.2018.10.24.23.48.07 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 24 Oct 2018 23:48:08 -0700 (PDT) Date: Thu, 25 Oct 2018 15:48:04 +0900 From: Sergey Senozhatsky To: Heiko Carstens Cc: Sergey Senozhatsky , Martin Schwidefsky , linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, Sergey Senozhatsky , Peter Oberparleiter Subject: Re: [PATCH] s390/fault: use wake_up_klogd() in bust_spinlocks() Message-ID: <20181025064804.GA20702@jagdpanzerIV> References: <20181024043048.21248-1-sergey.senozhatsky@gmail.com> <20181024043425.GA8862@jagdpanzerIV> <20181025062800.GB4037@osiris> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181025062800.GB4037@osiris> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On (10/25/18 08:28), Heiko Carstens wrote: [..] > > int loglevel_save = console_loglevel; > > - console_unblank(); > > - oops_in_progress = 0; > > - /* > > - * OK, the message is on the console. Now we call printk() > > - * without oops_in_progress set so that printk will give klogd > > - * a poke. Hold onto your hats... > > - */ > > + > > console_loglevel = 15; > > - printk(" "); > > + console_unblank(); > > console_loglevel = loglevel_save; > > + oops_in_progress = 0; > > + wake_up_klogd(); > > } > > With your patch this looks nearly like the common code variant. I did > some code archaeology and this function is unchanged since ~17 years. > When it was introduced it was close to identical to the x86 variant. > All other architectures use the common code variant in the > meantime. So if we change this I'd prefer that we switch s390 to the > common code variant as well. Right. I couldn't clearly understand what was so special that s390 bust_spinlock() was doing, but assumed that this `console_loglevel' manipulation probably was somehow important to s390. Though this console_loglevel adjustment is not 100% guaranteed to make any difference, because of the way console_unblank() works: if it can't lock console_sem and it sees oops_in_progress then it does nothing; it doesn't even print logbuf messages to the consoles. If, however, console_sem is not locked, then it does print pending logbuf messages, with temporarily verbose console_loglevel. I concluded that this might be important to you in one way or another. > Right now I can't see a reason for not doing that, but I might be > wrong of course. So, could you please provide a new version which just > removes this variant and makes s390 use the generic one too. > > We'll see if there is any fallout... Will do! Sounds good. -ss