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Subject: Re: [PATCH v2 14/30] cxlflash: Fix to avoid stall while waiting on TMF
To: "Matthew R. Ochs" <mrochs@linux.vnet.ibm.com>, linux-scsi@vger.kernel.org,
 James Bottomley <James.Bottomley@HansenPartnership.com>,
 "Nicholas A. Bellinger" <nab@linux-iscsi.org>,
 Ian Munsie <imunsie@au1.ibm.com>, Daniel Axtens <dja@ozlabs.au.ibm.com>,
 Andrew Donnellan <andrew.donnellan@au1.ibm.com>
References: <1442438635-49044-1-git-send-email-mrochs@linux.vnet.ibm.com>
 <1442439022-49742-1-git-send-email-mrochs@linux.vnet.ibm.com>
Cc: Michael Neuling <mikey@neuling.org>, linuxppc-dev@lists.ozlabs.org,
 "Manoj N. Kumar" <manoj@linux.vnet.ibm.com>
From: Brian King <brking@linux.vnet.ibm.com>
Message-ID: <56004B57.6080409@linux.vnet.ibm.com>
Date: Mon, 21 Sep 2015 13:24:23 -0500
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On 09/16/2015 04:30 PM, Matthew R. Ochs wrote:
> Borrowing the TMF waitq's spinlock causes a stall condition when
> waiting for the TMF to complete. To remedy, introduce our own spin
> lock to serialize TMF and use the appropriate wait services.

Can you clarify what stall condition you were seeing. Its not obvious
to me what this fixes. Do you have softlockup logs from the failure?

-Brian

-- 
Brian King
Power Linux I/O
IBM Linux Technology Center