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References: <20220211110423.22733-1-andriy.shevchenko@linux.intel.com> <Yh+SHs4CEWkiLxAe@smile.fi.intel.com>
In-Reply-To: <Yh+SHs4CEWkiLxAe@smile.fi.intel.com>
From: "Rafael J. Wysocki" <rafael@kernel.org>
Date: Wed, 2 Mar 2022 17:36:20 +0100
Message-ID: <CAJZ5v0g_3a7A5aFab6ZsM8nPDmivoTeNgdSG17Lt71mFKmNxmg@mail.gmail.com>
Subject: Re: [PATCH v1 1/1] ACPI: Switch to use list_entry_is_head() helper
To: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>, Hui Wang <hui.wang@canonical.com>, 
	ACPI Devel Maling List <linux-acpi@vger.kernel.org>, 
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>, nvdimm@lists.linux.dev, 
	"Rafael J. Wysocki" <rafael@kernel.org>, Len Brown <lenb@kernel.org>, 
	Dan Williams <dan.j.williams@intel.com>, Vishal Verma <vishal.l.verma@intel.com>, 
	Dave Jiang <dave.jiang@intel.com>, Ira Weiny <ira.weiny@intel.com>
Content-Type: text/plain; charset="UTF-8"

On Wed, Mar 2, 2022 at 4:50 PM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
>
> On Fri, Feb 11, 2022 at 01:04:23PM +0200, Andy Shevchenko wrote:
> > Since we got list_entry_is_head() helper in the generic header,
> > we may switch the ACPI modules to use it. This eliminates the
> > need in additional variable. In some cases it reduces critical
> > sections as well.
>
> Besides the work required in a couple of cases (LKP) there is an
> ongoing discussion about list loops (and this particular API).
>
> Rafael, what do you think is the best course of action here?

I think the current approach is to do the opposite of what this patch
is attempting to do: avoid using the list iterator outside of the
loop.