NVDIMM Device and Persistent Memory development
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From: Christoph Hellwig <hch@infradead.org>
To: "Dennis.Wu" <dennis.wu@intel.com>
Cc: nvdimm@lists.linux.dev, dan.j.williams@intel.com,
	vishal.l.verma@intel.com, dave.jiang@intel.com,
	ira.weiny@intel.com
Subject: Re: [PATCH] ACPI/NFIT: Add no_deepflush param to dynamic control flush operation
Date: Wed, 29 Jun 2022 08:27:03 -0700	[thread overview]
Message-ID: <YrxvR6zDZymsQCQl@infradead.org> (raw)
In-Reply-To: <20220629083118.8737-1-dennis.wu@intel.com>

On Wed, Jun 29, 2022 at 04:31:18PM +0800, Dennis.Wu wrote:
> reason: in the current BTT implimentation deepflush is always
> used and deepflush is very expensive. Since customer already
> know the ADR can protect the WPQ data in memory controller and
> no need to call deepflush to get better performance. BTT w/o
> deepflush, performance can improve 300%~600% with diff FIO jobs.
> 
> How: Add one param "no_deepflush" in the nfit module parameter.
> if "modprob nfit no_deepflush=1", customer can get the higher
> performance but not strict data security. Before modprob nfit,
> you may need to "ndctl disable-region".

This goes back to my question from years ago:  why do we ever
do this deep flush in the Linux nvdimm stack to start with?

  reply	other threads:[~2022-06-29 15:27 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-06-29  8:31 [PATCH] ACPI/NFIT: Add no_deepflush param to dynamic control flush operation Dennis.Wu
2022-06-29 15:27 ` Christoph Hellwig [this message]
2022-07-13  1:25   ` Dan Williams
2022-07-20  6:24     ` Christoph Hellwig
2022-09-20  3:08       ` Wu, Dennis
2022-09-20 11:46         ` Christoph Hellwig
2022-09-20 19:30       ` Dan Williams
2022-10-20  6:23         ` Wu, Dennis

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