From: Arun KS <arunks@codeaurora.org>
To: Julia Lawall <julia.lawall@lip6.fr>
Cc: Michal Hocko <mhocko@kernel.org>,
Arun Sudhilal <getarunks@gmail.com>,
linux-kernel@vger.kernel.org, linux-mm <linux-mm@kvack.org>,
Minchan Kim <minchan@kernel.org>, Michal Hocko <mhocko@suse.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH] mm: convert totalram_pages, totalhigh_pages and managed_pages to atomic.
Date: Thu, 25 Oct 2018 11:01:41 +0530 [thread overview]
Message-ID: <9bd14fb3c0ce8ca9a33c33ce81e66037@codeaurora.org> (raw)
In-Reply-To: <alpine.DEB.2.21.1810230711220.2343@hadrien>
On 2018-10-23 11:43, Julia Lawall wrote:
> On Tue, 23 Oct 2018, Michal Hocko wrote:
>
>> [Trimmed CC list + Julia - there is indeed no need to CC everybody
>> maintain a
>> file you are updating for the change like this]
>>
>> On Tue 23-10-18 10:16:51, Arun Sudhilal wrote:
>> > On Mon, Oct 22, 2018 at 11:41 PM Michal Hocko <mhocko@kernel.org> wrote:
>> > >
>> > > On Mon 22-10-18 22:53:22, Arun KS wrote:
>> > > > Remove managed_page_count_lock spinlock and instead use atomic
>> > > > variables.
>> > >
>> >
>> > Hello Michal,
>> > > I assume this has been auto-generated. If yes, it would be better to
>> > > mention the script so that people can review it and regenerate for
>> > > comparision. Such a large change is hard to review manually.
>> >
>> > Changes were made partially with script. For totalram_pages and
>> > totalhigh_pages,
>> >
>> > find dir -type f -exec sed -i
>> > 's/totalram_pages/atomic_long_read(\&totalram_pages)/g' {} \;
>> > find dir -type f -exec sed -i
>> > 's/totalhigh_pages/atomic_long_read(\&totalhigh_pages)/g' {} \;
>> >
>> > For managed_pages it was mostly manual edits after using,
>> > find mm/ -type f -exec sed -i
>> > 's/zone->managed_pages/atomic_long_read(\&zone->managed_pages)/g' {}
>> > \;
>>
>> I guess we should be able to use coccinelle for this kind of change
>> and
>> reduce the amount of manual intervention to absolute minimum.
>
> Coccinelle looks like it would be desirable, especially in case the
> word
> zone is not always used.
>
> Arun, please feel free to contact me if you want to try it and need
> help.
Hello Julia,
I was able to come up .cocci for replacing managed_pages,
@@
struct zone *z;
@@
(
z->managed_pages = ...
|
- z->managed_pages
+ atomic_long_read(&z->managed_pages)
)
@@
struct zone *z;
expression e1;
@@
- z->managed_pages = e1
+ atomic_long_set(&z->managed_pages, e1)
@@
expression e,e1;
@@
- e->managed_pages += e1
+ atomic_long_add(e1, &e->managed_pages)
@@
expression z;
@@
- z.managed_pages
+ atomic_long_read(&z.managed_pages)
But I m not able to use same method for unsigned long
variables(totalram_pages)
@@
unsigned long totalram_pages;
@@
(
totalram_pages = ...
|
-totalram_pages
+atomic_long_read(&totalram_pages)
)
This throws error,
spatch test1.cocci mm/page_alloc.c
init_defs_builtins: /usr/lib/coccinelle/standard.h
HANDLING: mm/page_alloc.c
previous modification:
MINUS
>>> atomic_long_read(&rule starting on line 1:totalram_pages)
According to environment 1:
rule starting on line 1.totalram_pages -> page_idx ^ (1 <<
order)
current modification:
MINUS
>>> atomic_long_read(&rule starting on line 1:totalram_pages)
According to environment 1:
rule starting on line 1.totalram_pages -> page_idx
Fatal error: exception Failure("rule starting on line 1: already tagged
token:
C code context
File "mm/internal.h", line 175, column 8, charpos = 5368
around = 'page_idx', whole content = return page_idx ^ (1 <<
order);")
Regards,
Arun
>
> julia
prev parent reply other threads:[~2018-10-25 5:31 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1540229092-25207-1-git-send-email-arunks@codeaurora.org>
[not found] ` <c57bcc584b3700c483b0311881ec3ae8786f88b1.camel@perches.com>
2018-10-23 5:11 ` [PATCH] mm: convert totalram_pages, totalhigh_pages and managed_pages to atomic Konstantin Khlebnikov
2018-10-23 20:04 ` Kees Cook
2018-10-24 5:17 ` Arun KS
2018-10-24 6:15 ` Michal Hocko
2018-10-24 6:26 ` Joe Perches
2018-10-24 8:23 ` Michal Hocko
2018-10-24 8:39 ` Joe Perches
2018-10-25 9:21 ` Michal Hocko
[not found] ` <20181022181122.GK18839@dhcp22.suse.cz>
[not found] ` <CABOM9Zpq41Ox8wQvsNjgfCtwuqh6CnyeW1B09DWa1TQN+JKf0w@mail.gmail.com>
2018-10-23 5:33 ` Michal Hocko
2018-10-23 6:13 ` Julia Lawall
2018-10-23 7:11 ` Arun Sudhilal
2018-10-25 5:31 ` Arun KS [this message]
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