From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alain Kalker Subject: Re: [PATCH V2] sd: Reduce log level to KERN_NOTICE for missing caching mode page Date: Mon, 02 Jun 2014 21:08:17 +0200 Message-ID: <538CCBA1.7060808@gmail.com> References: <1401734883-9540-1-git-send-email-a.c.kalker@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mail-wg0-f43.google.com ([74.125.82.43]:55312 "EHLO mail-wg0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751309AbaFBTIV (ORCPT ); Mon, 2 Jun 2014 15:08:21 -0400 Received: by mail-wg0-f43.google.com with SMTP id l18so5503318wgh.26 for ; Mon, 02 Jun 2014 12:08:20 -0700 (PDT) In-Reply-To: <1401734883-9540-1-git-send-email-a.c.kalker@gmail.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: linux-scsi@vger.kernel.org Cc: "James E.J. Bottomley" , "Martin K. Petersen" On 06/02/2014 08:48 PM, Alain Kalker wrote: > Reduce the lernel log level to KERN_NOTICE for messages related > to a missing caching mode page. There is an open bug report at kernel.org (dating all the way back to=20 Linux 2.6.34.1) about this: Bug 16490 =96 "Assuming drive cache: write through" messages probably h= ave=20 wrong loglevel : https://bugzilla.kernel.org/show_bug.cgi?id=3D16490 Also, many people are asking questions about this on internet fora,=20 submitting bug reports to bugtrackers for their distributions,=20 apparently the error log level makes them think their system is=20 malfunctioning in some way. > Reasons why I think this change is justified: > - The condition is not an error; the existing workaround of assuming > a write through cache doesn't limit functionality in any way. > - It doesn't warrant a warning either: as it is most likely > a hardware limitation, there is little that an ordinary user can d= o > about it besides replacing the affected hardware. > Making it a warning would still break quiet boot (kernel commandli= ne > parameter 'quiet'), and may still trip log monitoring software > unneccessarily, either on every boot or whenever an affected > external device is plugged in. > - It should be a notice, for it is a normal but significant condition= , > as it may impact write performance. This would bring it on par wit= h > the log messages in the same function. > > Signed-off-by: Alain Kalker > --- > drivers/scsi/sd.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c > index efcbcd1..5f0f6c6 100644 > --- a/drivers/scsi/sd.c > +++ b/drivers/scsi/sd.c > @@ -2442,7 +2442,7 @@ sd_read_cache_type(struct scsi_disk *sdkp, unsi= gned char *buffer) > } > } > > - sd_first_printk(KERN_ERR, sdkp, "No Caching mode page found\n"); > + sd_first_printk(KERN_NOTICE, sdkp, "No Caching mode page found\n")= ; > goto defaults; > > Page_found: > @@ -2489,7 +2489,7 @@ defaults: > "Assuming drive cache: write back\n"); > sdkp->WCE =3D 1; > } else { > - sd_first_printk(KERN_ERR, sdkp, > + sd_first_printk(KERN_NOTICE, sdkp, > "Assuming drive cache: write through\n"); > sdkp->WCE =3D 0; > } > -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html