From: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
To: Dave Rodgman <dave.rodgman@arm.com>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
nd <nd@arm.com>,
"herbert@gondor.apana.org.au" <herbert@gondor.apana.org.au>,
"davem@davemloft.net" <davem@davemloft.net>,
Matt Sealey <Matt.Sealey@arm.com>,
"nitingupta910@gmail.com" <nitingupta910@gmail.com>,
"rpurdie@openedhand.com" <rpurdie@openedhand.com>,
"markus@oberhumer.com" <markus@oberhumer.com>,
"minchan@kernel.org" <minchan@kernel.org>,
"sergey.senozhatsky.work@gmail.com"
<sergey.senozhatsky.work@gmail.com>,
"sonnyrao@google.com" <sonnyrao@google.com>,
"gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
"akpm@linux-foundation.org" <akpm@linux-foundation.org>
Subject: Re: [PATCH v2 0/7] lib/lzo: performance improvements
Date: Thu, 29 Nov 2018 13:46:06 +0900 [thread overview]
Message-ID: <20181129044606.GI6379@jagdpanzerIV> (raw)
In-Reply-To: <20181127161913.23863-1-dave.rodgman@arm.com>
On (11/27/18 16:19), Dave Rodgman wrote:
> > Right. The number is data dependent. Not all swapped out pages can be
> > compressed; compressed pages that end up being >= zs_huge_class_size() are
> > considered incompressible and stored as it.
> >
> > I'd say that on my setups around 50-60% of pages are incompressible.
>
> So, just to give a bit more detail: the test setup was a Samsung
> Chromebook Pro, cycling through 80 tabs in Chrome. With lzo-rle, only
> 5% of pages increased in size, and 90% of pages compress to 75% of
> original size (or better). Mean compression ratio was 41%. Importantly
> for lzo-rle, there are a lot of low-entropy pages where it can do well:
> in total about 20% of the data is zeros forming part of a run of 4 or
> more bytes.
>
> As a quick summary of the impact of these patches on bigger chunks of
> data, I've compared the performance of four different variants of lzo
> on two large (~40 MB) files. The numbers show round-trip throughput
> in MB/s:
>
> Variant | Low-entropy | High-entropy
> Current lzo | 242 | 157
> Arm opts | 290 | 159
> RLE | 876 | 151
> Arm opts + RLE | 1150 | 181
>
> So both the Arm optimisations (8,16-byte copy & CTZ patches), and the
> RLE implementation make a significant contribution to the overall
> performance uplift.
Cool!
-ss
prev parent reply other threads:[~2018-11-29 4:46 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-27 16:19 [PATCH v2 0/7] lib/lzo: performance improvements Dave Rodgman
2018-11-27 16:19 ` [PATCH 1/7] lib/lzo: tidy-up ifdefs Dave Rodgman
2018-11-27 16:19 ` [PATCH 2/7] lib/lzo: clean-up by introducing COPY16 Dave Rodgman
2018-11-27 22:50 ` Andrew Morton
2018-11-27 16:19 ` [PATCH 3/7] lib/lzo: enable 64-bit CTZ on Arm Dave Rodgman
2018-11-27 16:19 ` [PATCH 4/7] lib/lzo: 64-bit CTZ on arm64 Dave Rodgman
2018-11-27 16:19 ` [PATCH 5/7] lib/lzo: fast 8-byte copy " Dave Rodgman
2018-11-27 16:19 ` [PATCH 6/7] lib/lzo: implement run-length encoding Dave Rodgman
2018-11-29 3:08 ` Sergey Senozhatsky
2018-11-29 3:11 ` Sergey Senozhatsky
2018-11-27 16:19 ` [PATCH 7/7] lib/lzo: separate lzo-rle from lzo Dave Rodgman
2018-11-29 4:43 ` Sergey Senozhatsky
2018-11-29 10:21 ` Dave Rodgman
2018-11-29 20:32 ` Andrew Morton
2018-11-30 3:05 ` Sergey Senozhatsky
2018-11-30 10:45 ` Dave Rodgman
2018-12-03 2:40 ` Sergey Senozhatsky
2018-12-03 2:53 ` Herbert Xu
2018-11-29 4:46 ` Sergey Senozhatsky [this message]
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