From:   Avri Altman <Avri.Altman@wdc.com>
To:     Jaegeuk Kim <jaegeuk@kernel.org>,
        "hch@infradead.org" <hch@infradead.org>
CC:     "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "linux-scsi@vger.kernel.org" <linux-scsi@vger.kernel.org>,
        "Martin K . Petersen" <martin.petersen@oracle.com>,
        Bart Van Assche <bvanassche@acm.org>,
        Adrian Hunter <adrian.hunter@intel.com>,
        Bean Huo <beanhuo@micron.com>,
        Stanley Chu <stanley.chu@mediatek.com>,
        Can Guo <cang@codeaurora.org>
Subject: RE: [PATCH] scsi: ufs: support IO traces for zoned block device
Thread-Topic: [PATCH] scsi: ufs: support IO traces for zoned block device
Thread-Index: AQHZQXBsGby1i9hcaku76rZBxiJwZa7RFW+AgBJqjYCAAIlRUA==
Date:   Tue, 28 Feb 2023 07:28:35 +0000
Message-ID: <DM6PR04MB65751899638206110D3D8FC2FCAC9@DM6PR04MB6575.namprd04.prod.outlook.com>
References: <20230215190448.1687786-1-jaegeuk@kernel.org>
 <Y+3GzX6yMOKUFTh3@infradead.org> <Y/05p0jYrg2wfXw6@google.com>
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=20
> On 02/15, Christoph Hellwig wrote:
> > Why does UFS even have it's own common tracing instad of just relying
> > on the core SCSI one, and even worse pokes into command set specifics
> > which is a no-go for LLDDs.  This code simply needs to go away instead
> > of beeing "enhanced".
>=20
> I'm not sure how all the other vendors use the trace tho, at least to me,=
 it's
> quite useful when debugging any UFS-specific information such as group_id=
 and
> doorbell status along with the attached scsi command, in addition to the
> accurate latency measurements.
For us as well.
Moreover, we are mainly using upiu tracing which is not available at scsi M=
L.

Thanks,
Avri