Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
MIME-Version: 1.0
References: <cover.1626371112.git.zhansayabagdaulet@gmail.com>
 <343394260f599d940cacc37f1dcc0309239ae220.1626371112.git.zhansayabagdaulet@gmail.com>
 <YPB7rBlU1SinK6FR@casper.infradead.org>
In-Reply-To: <YPB7rBlU1SinK6FR@casper.infradead.org>
From:   Pavel Tatashin <pasha.tatashin@soleen.com>
Date:   Thu, 15 Jul 2021 14:21:21 -0400
Message-ID: <CA+CK2bCPMmbr+=h4evTkbJoEFQu_th_NOe0Gp11hU7xz3fLZ8A@mail.gmail.com>
Subject: Re: [PATCH 1/2] mm: KSM: fix ksm_run data type
To:     Matthew Wilcox <willy@infradead.org>
Cc:     Zhansaya Bagdauletkyzy <zhansayabagdaulet@gmail.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Tyler Hicks <tyhicks@linux.microsoft.com>,
        linux-mm <linux-mm@kvack.org>,
        LKML <linux-kernel@vger.kernel.org>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Thu, Jul 15, 2021 at 2:18 PM Matthew Wilcox <willy@infradead.org> wrote:
>
> On Fri, Jul 16, 2021 at 12:01:01AM +0600, Zhansaya Bagdauletkyzy wrote:
> > +++ b/mm/ksm.c
> > @@ -289,7 +289,7 @@ static int ksm_nr_node_ids = 1;
> >  #define KSM_RUN_MERGE        1
> >  #define KSM_RUN_UNMERGE      2
> >  #define KSM_RUN_OFFLINE      4
> > -static unsigned long ksm_run = KSM_RUN_STOP;
> > +static unsigned int ksm_run = KSM_RUN_STOP;
>
> Should this be an enum instead?

I think "unsigned int" is OK here, as it is exposed as uint to users:
Documentation/ABI/testing/sysfs-kernel-mm-ksm

/sys/kernel/mm/ksm/run

run: write 0 to disable ksm, read 0 while ksm is disabled.

- write 1 to run ksm, read 1 while ksm is running.
- write 2 to disable ksm and unmerge all its pages.

Pasha