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Date: Mon, 3 Jun 2024 12:27:56 -0700
From: Andi Kleen <ak@linux.intel.com>
To: Carlos Llamas <cmllamas@google.com>
Cc: linux-mm@kvack.org, Mike Kravetz <mike.kravetz@oracle.com>,
	Hugh Dickins <hughd@google.com>, Edward Liaw <edliaw@google.com>,
	kernel-team@android.com, linux-kernel@vger.kernel.org,
	linux-api@vger.kernel.org
Subject: Re: Header conflicts with shmget() and SHM_HUGE_2MB
Message-ID: <Zl4ZPIesxcxI-QE2@tassilo>
References: <Zl4LC9lTNptB2xTJ@google.com>
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> I can see such definitions are tagged as "obsolete" in the uapi headers.
> Do we need some ifndef protection with the glibc headers?

They should be still supported, but also the more generic macro.
> 
> What is the advice to follow for userspace? Skip <linux/shm.h> and
> openly redefine the SHM_HUGE_* wherever needed?

glibc (or other C libraries if not using linux/shm) should add the
defines.  Short term you would need to redefine on your own yes.

-Andi