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From: Shaohua Li <shli@kernel.org>
To: Artur Paszkiewicz <artur.paszkiewicz@intel.com>
Cc: Pawel Baldysiak <pawel.baldysiak@intel.com>, linux-raid@vger.kernel.org
Subject: Re: [PATCH 0/2] md: Add support for Multiple PPLs
Date: Mon, 28 Aug 2017 07:54:10 -0700	[thread overview]
Message-ID: <20170828145410.mhuwgvj2r7lqim4h@kernel.org> (raw)
In-Reply-To: <110e9aa4-4215-7f29-dd05-7d00dde6da9b@intel.com>

On Mon, Aug 28, 2017 at 09:44:20AM +0200, Artur Paszkiewicz wrote:
> On 08/25/2017 11:53 PM, Shaohua Li wrote:
> > On Fri, Aug 25, 2017 at 10:02:07PM +0200, Pawel Baldysiak wrote:
> >> On 08/21/2017 06:14 PM, Shaohua Li wrote> Can you elaborate more?
> >>>
> >> Storage presented to the host may have a RAID on the back-end. For NVMe
> >> SSDs, the 1.3 specification provided a field to advertise chunk
> >> boundaries: Identify Namespace NOIOB. We need to span the entire stripe
> >> to utilize the total available capacity, otherwise we'll repeatedly
> >> write to only a subset, increasing write amplification factor. The new
> >> PPL approach is designed to access the full capacity.
> > 
> > Ok, this makes sense. The 1MB area looks arbitrary though. What if the
> > chunk is 2MB? Could we make it configurable?
> 
> Actually, it is configurable by 'ppl_size' which comes from mdadm. The
> 1MB is what the current RSTe standard defines but it will be possible to
> change it without affecting the kernel.

ok, queued the patches, thanks!

      reply	other threads:[~2017-08-28 14:54 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-08-16 15:13 [PATCH 0/2] md: Add support for Multiple PPLs Pawel Baldysiak
2017-08-16 15:13 ` [PATCH 1/2] md: Runtime support for multiple ppls Pawel Baldysiak
2017-08-16 15:13 ` [PATCH 2/2] raid5-ppl: Recovery support for multiple partial parity logs Pawel Baldysiak
2017-08-17 18:03 ` [PATCH 0/2] md: Add support for Multiple PPLs Shaohua Li
2017-08-21 14:54   ` Pawel Baldysiak
2017-08-21 16:14     ` Shaohua Li
2017-08-25 20:02       ` Pawel Baldysiak
2017-08-25 21:53         ` Shaohua Li
2017-08-28  7:44           ` Artur Paszkiewicz
2017-08-28 14:54             ` Shaohua Li [this message]

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