Re: [RFC PATCH 4/8] mm/madvise: define madvise behavior in a struct

From: Nadav Amit
Date: Mon Sep 27 2021 - 16:36:25 EST

> On Sep 27, 2021, at 5:14 AM, Kirill A. Shutemov <kirill@xxxxxxxxxxxxx> wrote:
> On Mon, Sep 27, 2021 at 03:31:21AM -0700, Nadav Amit wrote:
>>> On Sep 27, 2021, at 2:31 AM, Kirill A. Shutemov <kirill@xxxxxxxxxxxxx> wrote:
>>> On Sun, Sep 26, 2021 at 09:12:55AM -0700, Nadav Amit wrote:
>>>> From: Nadav Amit <namit@xxxxxxxxxx>
>>>> The different behaviors of madvise are different in several ways, which
>>>> are distributed across several functions. Use the design pattern from
>>>> iouring in order to define the actions that are required for each
>>>> behavior.
>>>> The next patches will get rid of old helper functions that are modified
>>>> in this patch and the redundant use of array_index_nospec(). The next
>>>> patches will add more actions for each leaf into the new struct.

[ snip ]

>>> MADV_SOFT_OFFLINE+1 smells bad.
>> I can set another constant instead and let the compiler shout if anything
>> outside the array is initialized.
> I would rather introduce a function that would return struct madvise_info
> for a given behavior. The function would have a switch inside. The default:
> may have BUILD_BUG() or something.

Sounds better than my solution. I will do so.