From: "Martin K. Petersen" <martin.petersen@oracle.com>
To: Finn Thain <fthain@telegraphics.com.au>
Cc: "James E.J. Bottomley" <jejb@linux.vnet.ibm.com>,
"Martin K. Petersen" <martin.petersen@oracle.com>,
Geert Uytterhoeven <geert@linux-m68k.org>,
linux-scsi@vger.kernel.org, linux-m68k@vger.kernel.org,
linux-kernel@vger.kernel.org,
Michael Schmitz <schmitzmic@gmail.com>
Subject: Re: [PATCH v2 3/3] scsi/ncr5380: Improve interrupt latency during PIO tranfers
Date: Wed, 14 Sep 2016 14:12:29 -0400 [thread overview]
Message-ID: <yq1twdil59u.fsf@sermon.lab.mkp.net> (raw)
In-Reply-To: <20160831044453.413698369@telegraphics.com.au> (Finn Thain's message of "Wed, 31 Aug 2016 14:44:56 +1000")
>>>>> "Finn" == Finn Thain <fthain@telegraphics.com.au> writes:
Finn> Large PIO transfers are broken up into chunks to try to avoid
Finn> disabling local IRQs for long periods. But IRQs are still disabled
Finn> for too long and this causes SCC FIFO overruns during serial port
Finn> transfers.
Finn> This patch reduces the PIO chunk size to reduce interrupt latency
Finn> to something on the order of milliseconds, at the expense of
Finn> additional CPU overhead from extra iterations of the
Finn> NCR5380_main() loop.
Applied to 4.9/scsi-queue.
--
Martin K. Petersen Oracle Linux Engineering
WARNING: multiple messages have this Message-ID (diff)
From: "Martin K. Petersen" <martin.petersen@oracle.com>
To: Finn Thain <fthain@telegraphics.com.au>
Cc: "James E.J. Bottomley" <jejb@linux.vnet.ibm.com>,
"Martin K. Petersen" <martin.petersen@oracle.com>,
Geert Uytterhoeven <geert@linux-m68k.org>,
<linux-scsi@vger.kernel.org>, <linux-m68k@vger.kernel.org>,
<linux-kernel@vger.kernel.org>,
Michael Schmitz <schmitzmic@gmail.com>
Subject: Re: [PATCH v2 3/3] scsi/ncr5380: Improve interrupt latency during PIO tranfers
Date: Wed, 14 Sep 2016 14:12:29 -0400 [thread overview]
Message-ID: <yq1twdil59u.fsf@sermon.lab.mkp.net> (raw)
In-Reply-To: <20160831044453.413698369@telegraphics.com.au> (Finn Thain's message of "Wed, 31 Aug 2016 14:44:56 +1000")
>>>>> "Finn" == Finn Thain <fthain@telegraphics.com.au> writes:
Finn> Large PIO transfers are broken up into chunks to try to avoid
Finn> disabling local IRQs for long periods. But IRQs are still disabled
Finn> for too long and this causes SCC FIFO overruns during serial port
Finn> transfers.
Finn> This patch reduces the PIO chunk size to reduce interrupt latency
Finn> to something on the order of milliseconds, at the expense of
Finn> additional CPU overhead from extra iterations of the
Finn> NCR5380_main() loop.
Applied to 4.9/scsi-queue.
--
Martin K. Petersen Oracle Linux Engineering
next prev parent reply other threads:[~2016-09-14 18:12 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-27 2:29 [PATCH 0/3] Small fixes and cleanup Finn Thain
2016-08-27 2:29 ` Finn Thain
2016-08-27 2:29 ` [PATCH 1/3] documentation/scsi: Remove nodisconnect parameter Finn Thain
2016-08-27 2:29 ` Finn Thain
2016-08-28 8:07 ` Geert Uytterhoeven
2016-09-06 12:41 ` Jonathan Corbet
2016-09-06 12:41 ` Jonathan Corbet
2016-08-27 2:30 ` [PATCH 2/3] scsi/ncr5380: Avoid a compiler warning Finn Thain
2016-08-27 2:30 ` Finn Thain
2016-08-28 8:08 ` Geert Uytterhoeven
2016-08-27 2:30 ` [PATCH 3/3] scsi/ncr5380: Improve interrupt latency during PIO tranfers Finn Thain
2016-08-27 2:30 ` Finn Thain
2016-08-28 8:08 ` Geert Uytterhoeven
2016-08-29 4:06 ` Finn Thain
2016-08-31 4:44 ` [PATCH v2 " Finn Thain
2016-08-31 4:44 ` Finn Thain
2016-08-31 14:07 ` Laurence Oberman
2016-09-09 11:28 ` Martin K. Petersen
2016-09-09 11:28 ` Martin K. Petersen
2016-09-09 12:00 ` Geert Uytterhoeven
2016-09-14 18:12 ` Martin K. Petersen [this message]
2016-09-14 18:12 ` Martin K. Petersen
2016-08-31 4:26 ` [PATCH 0/3] Small fixes and cleanup Martin K. Petersen
2016-08-31 4:26 ` Martin K. Petersen
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