From: Daniel Walker <danielwa@cisco.com>
To: David Woodhouse <dwmw2@infradead.org>
Cc: "Nikunj Kela (nkela)" <nkela@cisco.com>,
Richard Weinberger <richard.weinberger@gmail.com>,
"linux-mtd @ lists . infradead . org"
<linux-mtd@lists.infradead.org>,
LKML <linux-kernel@vger.kernel.org>,
"xe-linux-external(mailer list)" <xe-linux-external@cisco.com>
Subject: Re: [PATCH] jffs2: implement mount option to configure endianness
Date: Tue, 13 Nov 2018 13:01:26 -0800 [thread overview]
Message-ID: <20181113210126.7cupw5gt3vpnyotq@zorba> (raw)
In-Reply-To: <b797e897960c3c047dfc7874615358a5443038a8.camel@infradead.org>
On Mon, Nov 12, 2018 at 03:43:37PM -0800, David Woodhouse wrote:
>
> That can't hurt. We should probably look at the time elapsed before you
> can *write* to it (when the background scan and crc checking is
> complete) rather than just reading.
>
Here are more data points. This is again with 100meg mtdram size. I made a
script which does the mount and umount, then perf ran that 100 times over and
averaged the results.
Baseline,
Performance counter stats for 'bash test.sh' (100 runs):
111.414863 task-clock # 0.637 CPUs utilized ( +- 0.07% )
41 context-switches # 0.371 K/sec ( +- 0.50% )
3 cpu-migrations # 0.023 K/sec ( +- 2.44% )
405 page-faults # 0.004 M/sec ( +- 0.05% )
147235193 cycles # 1.322 GHz ( +- 0.47% ) [53.76%]
53688988 stalled-cycles-frontend # 36.46% frontend cycles idle ( +- 2.59% ) [45.13%]
21691444 stalled-cycles-backend # 14.73% backend cycles idle ( +- 5.81% ) [68.50%]
138433181 instructions # 0.94 insns per cycle
# 0.39 stalled cycles per insn ( +- 0.88% ) [88.11%]
25882823 branches # 232.310 M/sec ( +- 1.42% ) [85.33%]
644457 branch-misses # 2.49% of all branches ( +- 5.19% ) [74.30%]
0.175012976 seconds time elapsed ( +- 0.58% )
With Nikunj's patch,
Performance counter stats for 'bash test.sh' (100 runs):
110.436715 task-clock # 0.625 CPUs utilized ( +- 0.07% )
41 context-switches # 0.373 K/sec ( +- 0.58% )
3 cpu-migrations # 0.024 K/sec ( +- 2.18% )
405 page-faults # 0.004 M/sec ( +- 0.05% )
145964351 cycles # 1.322 GHz ( +- 0.49% ) [53.68%]
47504491 stalled-cycles-frontend # 32.55% frontend cycles idle ( +- 2.96% ) [55.47%]
20481138 stalled-cycles-backend # 14.03% backend cycles idle ( +- 6.18% ) [71.19%]
134947645 instructions # 0.92 insns per cycle
# 0.35 stalled cycles per insn ( +- 1.18% ) [82.19%]
25343960 branches # 229.489 M/sec ( +- 1.65% ) [82.50%]
693642 branch-misses # 2.74% of all branches ( +- 5.29% ) [70.06%]
0.176606850 seconds time elapsed ( +- 0.50% )
This seems to show an 0.91% speed elapsed time difference. Most of the rest of it seems very similar.
Daniel
prev parent reply other threads:[~2018-11-13 21:01 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-06 21:49 [PATCH] jffs2: implement mount option to configure endianness Nikunj Kela
2018-11-07 9:05 ` David Woodhouse
2018-11-07 9:16 ` Joakim Tjernlund
2018-11-07 16:12 ` David Woodhouse
2018-11-07 17:33 ` Daniel Walker
2018-11-07 17:58 ` David Woodhouse
2018-11-07 18:41 ` Joakim Tjernlund
2018-11-08 15:25 ` Christoph Hellwig
2018-11-07 19:21 ` Daniel Walker
2018-11-07 18:04 ` Nikunj Kela (nkela)
2018-11-07 18:14 ` Richard Weinberger
2018-11-08 8:11 ` David Woodhouse
2018-11-08 18:01 ` Nikunj Kela (nkela)
2018-11-08 18:50 ` Joakim Tjernlund
2018-11-08 19:47 ` David Woodhouse
2018-11-12 21:43 ` Daniel Walker
2018-11-12 22:50 ` Daniel Walker
2018-11-12 23:11 ` David Woodhouse
2018-11-12 23:40 ` Daniel Walker
2018-11-12 23:43 ` David Woodhouse
2018-11-13 0:06 ` Daniel Walker
2018-11-13 21:01 ` Daniel Walker [this message]
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