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From: "Maciej W. Rozycki" <macro@wdc.com>
To: Mikulas Patocka <mpatocka@redhat.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>,
	"Maciej W. Rozycki" <macro@linux-mips.org>,
	Arnd Bergmann <arnd@arndb.de>,
	Richard Henderson <rth@twiddle.net>,
	Matt Turner <mattst88@gmail.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	alpha <linux-alpha@vger.kernel.org>,
	linux-serial@vger.kernel.org, linux-rtc@vger.kernel.org
Subject: Re: [PATCH v5] alpha: fix memory barriers so that they conform to the specification
Date: Mon, 25 May 2020 17:39:14 +0100 (BST)
Message-ID: <alpine.LFD.2.21.2005251729110.21168@redsun52.ssa.fujisawa.hgst.com> (raw)
In-Reply-To: <alpine.LRH.2.02.2005251149540.4135@file01.intranet.prod.int.rdu2.redhat.com>

On Mon, 25 May 2020, Mikulas Patocka wrote:

> > > The functions __raw_read* are already extern inline, so the compiler will 
> > > inline/noinline them depending on the macros trivial_io_bw and 
> > > trivial_io_lq - so we can just call them from read*_relaxed without 
> > > repeating the extern inline pattern.
> > 
> >  The whole point of this peculiar arrangement for cooked accessors is to 
> > avoid having barriers inserted inline around out-of-line calls to raw 
> > accessors,
> 
> I see, but why do we want to avoid that? Linux kernel has no binary 
> compatibility, so it doesn't matter if the barriers are inlined in the 
> drivers or not.

 It does matter as it expands code unnecessarily (at all call sites), as I 
noted in the original review.  This has nothing to do with compatibility.

> Anyway, I've sent a next version of the patch that makes read*_relaxed 
> extern inline.

 Thanks, I'll have a look.  And now that you have this update, please run 
`size' on ALPHA_GENERIC `vmlinux', preferably monolithic, to see what the 
difference is between `read*_relaxed' handlers `static inline' and keyed 
with `*trivial_rw_*'.

  Maciej

  reply index

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-06 11:21 [PATCH 1/2] alpha: add a delay between RTC port write and read Mikulas Patocka
2020-05-06 14:20 ` Arnd Bergmann
2020-05-06 17:12   ` [PATCH 1/2 v2] alpha: add a delay to inb_p, inb_w and inb_l Mikulas Patocka
2020-05-07  8:06     ` [PATCH 1/2 v3] " Mikulas Patocka
2020-05-07  8:20       ` Greg Kroah-Hartman
2020-05-07 10:53         ` Mikulas Patocka
2020-05-07 13:30       ` Arnd Bergmann
2020-05-07 14:09         ` Mikulas Patocka
2020-05-07 15:08           ` Arnd Bergmann
2020-05-07 15:45             ` Mikulas Patocka
2020-05-07 15:46             ` [PATCH v4] alpha: add a barrier after outb, outw and outl Mikulas Patocka
2020-05-07 19:12               ` Arnd Bergmann
2020-05-10  1:27                 ` Maciej W. Rozycki
2020-05-10  1:25             ` [PATCH 1/2 v3] alpha: add a delay to inb_p, inb_w and inb_l Maciej W. Rozycki
2020-05-10 18:50               ` Mikulas Patocka
2020-05-11 14:58                 ` Maciej W. Rozycki
2020-05-12 19:35                   ` Mikulas Patocka
2020-05-13 14:41                   ` Ivan Kokshaysky
2020-05-13 16:13                     ` Greg Kroah-Hartman
2020-05-13 17:17                     ` Maciej W. Rozycki
2020-05-22 13:03                       ` Mikulas Patocka
2020-05-22 13:37                         ` Maciej W. Rozycki
2020-05-22 13:26                     ` Mikulas Patocka
2020-05-22 20:00                       ` Mikulas Patocka
2020-05-23 10:26                         ` [PATCH v4] alpha: fix memory barriers so that they conform to the specification Mikulas Patocka
2020-05-23 15:10                           ` Ivan Kokshaysky
2020-05-23 15:34                             ` Mikulas Patocka
2020-05-23 15:37                               ` [PATCH v5] " Mikulas Patocka
2020-05-24 14:54                                 ` Maciej W. Rozycki
2020-05-25 13:56                                   ` Mikulas Patocka
2020-05-25 14:07                                     ` Arnd Bergmann
2020-05-25 14:45                                     ` Maciej W. Rozycki
2020-05-25 15:53                                       ` [PATCH v6] " Mikulas Patocka
2020-05-26 14:47                                         ` [PATCH v7] " Mikulas Patocka
2020-05-27  0:18                                           ` Maciej W. Rozycki
2020-06-08  6:58                                             ` Mikulas Patocka
2020-06-08 23:49                                               ` Matt Turner
2020-05-25 15:54                                       ` [PATCH v5] " Mikulas Patocka
2020-05-25 16:39                                         ` Maciej W. Rozycki [this message]
2020-05-26 14:48                                           ` Mikulas Patocka
2020-05-27  0:23                                             ` Maciej W. Rozycki
2020-05-23 16:44                               ` [PATCH v4] " Maciej W. Rozycki
2020-05-23 17:09                                 ` Mikulas Patocka
2020-05-23 19:27                                   ` Maciej W. Rozycki
2020-05-23 20:11                                     ` Mikulas Patocka

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