linux-kernel - RFC: Allow kfree to free all types of allocations ?

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Date:   Tue, 09 Jun 2020 15:50:42 -0700
From:   Joe Perches <joe@...ches.com>
To:     Linus Torvalds <torvalds@...ux-foundation.org>
Cc:     LKML <linux-kernel@...r.kernel.org>
Subject: RFC: Allow kfree to free all types of allocations ?

There are a lot of patches trying to match
various [kv].alloc allocations to specific frees.

But are there frees in a fast path?

Why not convert kfree to add a few extra tests
and add #defines for existing uses

Something like:

void kfree(const void *addr)
{
	if (is_kernel_rodata((unsigned long)addr))
		return;

	if (is_vmalloc_addr(addr))
		_vfree(addr);
	else
		_kfree(addr);
}

And add defines like:

#define kvfree		kfree
#define vfree		kfree
#define kfree_const	kfree

Does 4 extra tests really matter?