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From: James Smart <jsmart2021@gmail.com>
To: Johannes Thumshirn <jthumshirn@suse.de>
Cc: linux-scsi@vger.kernel.org,
	Dick Kennedy <dick.kennedy@broadcom.com>,
	James Smart <james.smart@broadcom.com>
Subject: Re: [PATCH v2 12/20] lpfc: Limit amount of work processed in IRQ
Date: Mon, 7 Aug 2017 13:50:59 -0700	[thread overview]
Message-ID: <389dd23c-6cc4-8498-5980-9fdd0610b516@gmail.com> (raw)
In-Reply-To: <20170807084354.GO3978@linux-x5ow.site>

On 8/7/2017 1:43 AM, Johannes Thumshirn wrote:
> On Fri, Aug 04, 2017 at 05:47:23PM -0700, James Smart wrote:
>> From: Dick Kennedy <dick.kennedy@broadcom.com>
>>
>> Various oops being seen on being in the ISR too long and cpu
>> lockups, when under heavy load.
>>
>> The amount of work being posted off of completion queues kept
>> the ISR running almost all the time
>>
>> Correct the issue by limiting the amount of work per itteration.
> 
> Have you considered using the IRQ poll mechanism for this? It deferres the
> heavy lifing into the Soft-IRQ layer and this could help you a lot here. IIRC
> I've sent James the "Slides" from my LSF/MM session which have the function
> protoypes on 'em. See 'lib/irq_poll.c' or the be2iscsi driver for further
> details.

We considered it, so far declined it - preferring the behavior of the 
dynamic hw coalescing we have. That said, we're already considering the 
softirq approach, which shouldn't be that large of a delta. However, 
we've chosen to delay that change while we harden the overall stability.

-- james

  reply	other threads:[~2017-08-07 20:51 UTC|newest]

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-08-05  0:47 [PATCH v2 00/20] lpfc updates for 11.4.0.3 James Smart
2017-08-05  0:47 ` [PATCH v2 01/20] lpfc: Fix plogi collision that causes illegal state transition James Smart
2017-08-07  7:49   ` Johannes Thumshirn
2017-08-05  0:47 ` [PATCH v2 02/20] lpfc: Fix loop mode target discovery James Smart
2017-08-07  7:55   ` Johannes Thumshirn
2017-08-05  0:47 ` [PATCH v2 03/20] lpfc: Fix rediscovery on switch blade pull James Smart
2017-08-07  7:56   ` Johannes Thumshirn
2017-08-05  0:47 ` [PATCH v2 04/20] lpfc: Fix oops when NVME Target is discovered in a nonNVME environment James Smart
2017-08-07  8:00   ` Johannes Thumshirn
2017-08-07 20:34     ` James Smart
2017-08-05  0:47 ` [PATCH v2 05/20] lpfc: convert info messages to standard messages James Smart
2017-08-07  8:00   ` Johannes Thumshirn
2017-08-05  0:47 ` [PATCH v2 06/20] lpfc: Correct return error codes to align with nvme_fc transport James Smart
2017-08-07  8:07   ` Johannes Thumshirn
2017-08-05  0:47 ` [PATCH v2 07/20] lpfc: Fix handling of FCP and NVME FC4 types in Pt2Pt topology James Smart
2017-08-07  8:18   ` Johannes Thumshirn
2017-08-05  0:47 ` [PATCH v2 08/20] lpfc: Fix duplicate NVME rport entries and namespaces James Smart
2017-08-07  8:33   ` Johannes Thumshirn
2017-08-05  0:47 ` [PATCH v2 09/20] lpfc: Fix crash in lpfc nvmet when fc port is reset James Smart
2017-08-07  8:34   ` Johannes Thumshirn
2017-08-05  0:47 ` [PATCH v2 10/20] lpfc: Fix NVME PRLI handling during RSCN James Smart
2017-08-07  8:35   ` Johannes Thumshirn
2017-08-05  0:47 ` [PATCH v2 11/20] lpfc: Correct issues with FAWWN and FDISCs James Smart
2017-08-05  0:47 ` [PATCH v2 12/20] lpfc: Limit amount of work processed in IRQ James Smart
2017-08-07  8:43   ` Johannes Thumshirn
2017-08-07 20:50     ` James Smart [this message]
2017-08-05  0:47 ` [PATCH v2 13/20] lpfc: Fix MRQ > 1 context list handling James Smart
2017-08-07  9:02   ` Johannes Thumshirn
2017-08-05  0:47 ` [PATCH v2 14/20] lpfc: Fix relative offset error on large nvmet target ios James Smart
2017-08-07  9:02   ` Johannes Thumshirn
2017-08-05  0:47 ` [PATCH v2 15/20] lpfc: Fix nvme target failure after 2nd adapter reset James Smart
2017-08-07  9:05   ` Johannes Thumshirn
2017-08-05  0:47 ` [PATCH v2 16/20] lpfc: Fix bad sgl reposting " James Smart
2017-08-07  9:06   ` Johannes Thumshirn
2017-08-05  0:47 ` [PATCH v2 17/20] lpfc: remove console log clutter James Smart
2017-08-07  9:06   ` Johannes Thumshirn
2017-08-05  0:47 ` [PATCH v2 18/20] lpfc: Add Buffer to Buffer credit recovery support James Smart
2017-08-07  9:08   ` Johannes Thumshirn
2017-08-05  0:47 ` [PATCH v2 19/20] scsi: lpfc: fix "integer constant too large" error on 32bit archs James Smart
2017-08-07  9:09   ` Johannes Thumshirn
2017-08-05  0:47 ` [PATCH v2 20/20] lpfc: lpfc version bump 11.4.0.3 James Smart
2017-08-07  9:08   ` Johannes Thumshirn

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