From: David Laight <David.Laight@ACULAB.COM>
To: 'Christophe Leroy' <christophe.leroy@csgroup.eu>,
Pavel Machek <pavel@denx.de>
Cc: Christoph Hellwig <hch@lst.de>, "arnd@arndb.de" <arnd@arndb.de>,
"gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH] /dev/zero: also implement ->read
Date: Mon, 7 Sep 2020 08:18:13 +0000 [thread overview]
Message-ID: <f09599c8e85940a6b34877854df241f8@AcuMS.aculab.com> (raw)
In-Reply-To: <7ece832b-e2b7-04af-f4bb-e84c909ee332@csgroup.eu>
From: Christophe Leroy
> Sent: 07 September 2020 05:44
...
> If you are talking about the tests around the set_fs series from
> Christoph, I identified that the degradation was linked to
> CONFIG_STACKPROTECTOR_STRONG being selected by default, which provides
> unreliable results from one patch to another, GCC doing some strange
> things linked to unrelated changes.
>
> With CONFIG_STACKPROTECTOR set to N, I get stable performance and no
> degradation with any of the patches of the set_fs series.
Ah I didn't spot that response going through.
Sounds like that option should be disabled if it causes that
much of a performance drop.
David
-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
next prev parent reply other threads:[~2020-09-07 8:18 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-03 15:59 Christoph Hellwig
2020-09-03 16:05 ` Christophe Leroy
2020-09-03 21:35 ` David Laight
2020-09-06 18:21 ` Pavel Machek
2020-09-06 18:35 ` Christophe Leroy
2020-09-06 18:38 ` Pavel Machek
2020-09-06 18:47 ` Christophe Leroy
2020-09-06 20:09 ` gregkh
2020-09-06 20:52 ` David Laight
2020-09-07 4:44 ` Christophe Leroy
2020-09-07 8:18 ` David Laight [this message]
2020-09-03 17:51 ` Christophe Leroy
2020-09-03 18:02 ` Greg KH
2020-09-06 22:34 ` Rasmus Villemoes
2020-09-07 6:20 ` Christoph Hellwig
2020-09-07 6:50 ` Rasmus Villemoes
2020-09-07 7:30 ` Christoph Hellwig
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