Re: [PATCH v6 3/6] mce: fix set_mce_nospec to always unmap the whole page

From: Jane Chu <jane.chu@oracle.com>
To: Christoph Hellwig <hch@infradead.org>
Cc: "david@fromorbit.com" <david@fromorbit.com>,
	"djwong@kernel.org" <djwong@kernel.org>,
	"dan.j.williams@intel.com" <dan.j.williams@intel.com>,
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	"dave.jiang@intel.com" <dave.jiang@intel.com>,
	"agk@redhat.com" <agk@redhat.com>,
	"snitzer@redhat.com" <snitzer@redhat.com>,
	"dm-devel@redhat.com" <dm-devel@redhat.com>,
	"ira.weiny@intel.com" <ira.weiny@intel.com>,
	"willy@infradead.org" <willy@infradead.org>,
	"vgoyal@redhat.com" <vgoyal@redhat.com>,
	"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
	"nvdimm@lists.linux.dev" <nvdimm@lists.linux.dev>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
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Subject: Re: [PATCH v6 3/6] mce: fix set_mce_nospec to always unmap the whole page
Date: Tue, 22 Mar 2022 22:45:01 +0000	[thread overview]
Message-ID: <fb1ca254-3e7d-0931-2bfa-8f7f27b7d4fd@oracle.com> (raw)
In-Reply-To: <YjmMWvDRUHE08T+a@infradead.org>

On 3/22/2022 1:44 AM, Christoph Hellwig wrote:
> On Sat, Mar 19, 2022 at 12:28:30AM -0600, Jane Chu wrote:
>> Mark poisoned page as not present, and to reverse the 'np' effect,
>> restate the _PAGE_PRESENT bit. Please refer to discussions here for
>> reason behind the decision.
>> https://lore.kernel.org/all/CAPcyv4hrXPb1tASBZUg-GgdVs0OOFKXMXLiHmktg_kFi7YBMyQ@mail.gmail.com/
> 
> I think it would be good to summarize the conclusion here instead of
> just linking to it.

Sure, will do.

> 
>> +static int _set_memory_present(unsigned long addr, int numpages)
>> +{
>> +	return change_page_attr_set(&addr, numpages, __pgprot(_PAGE_PRESENT), 0);
>> +}
> 
> What is the point of this trivial helper with a single caller?
> 

Okay, will remove the helper.

thanks!
-jane