From mboxrd@z Thu Jan  1 00:00:00 1970
From: Sasha Levin <sashal@kernel.org>
Subject: Re: [PATCH] IB/hfi1: Avoid hardlockup with flushlist_lock
Date: Mon, 24 Jun 2019 16:17:43 -0400
Message-ID: <20190624201743.GB3881@sasha-vm>
References: <20190624155601.134582.32938.stgit@awfm-01.aw.intel.com>
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To: Mike Marciniszyn <mike.marciniszyn@intel.com>
Cc: stable@vger.kernel.org, linux-rdma@vger.kernel.org, stable-commits@vger.kernel.org
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On Mon, Jun 24, 2019 at 11:56:02AM -0400, Mike Marciniszyn wrote:
>commit cf131a81967583ae737df6383a0893b9fee75b4e upstream.
>
>Heavy contention of the sde flushlist_lock can cause hard lockups at
>extreme scale when the flushing logic is under stress.
>
>Mitigate by replacing the item at a time copy to the local list with
>an O(1) list_splice_init() and using the high priority work queue to
>do the flushes.
>
>Ported to linux-4.9.y.

I've queued this one for 4.9 and 4.4, thank you.