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Date: Tue, 29 Mar 2016 19:41:05 -0400 (EDT)
Message-Id: <20160329.194105.2209941679960771383.davem@davemloft.net>
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Subject: Re: [PATCH v3] sparc64: Reduce TLB flushes during hugepte changes
From: David Miller <davem@davemloft.net>
In-Reply-To: <1459285913-141365-1-git-send-email-nitin.m.gupta@oracle.com>
References: <1459285913-141365-1-git-send-email-nitin.m.gupta@oracle.com>
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From: Nitin Gupta <nitin.m.gupta@oracle.com>
Date: Tue, 29 Mar 2016 14:11:14 -0700

> During hugepage map/unmap, TSB and TLB flushes are currently
> issued at every PAGE_SIZE'd boundary which is unnecessary.
> We now issue the flush at REAL_HPAGE_SIZE boundaries only.
> 
> Without this patch workloads which unmap a large hugepage
> backed VMA region get CPU lockups due to excessive TLB
> flush calls.
> 
> Orabug: 22365539, 22643230, 22995196
> 
> Signed-off-by: Nitin Gupta <nitin.m.gupta@oracle.com>

You really need to put some more work into this, there are lots of
config variants you didn't even test.

See the kbuild robot replies...