linux-kernel - Re: [tip: x86/mm] x86/mm/pat: Rename pat_rbtree.c to pat

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Message-ID: <20191121170849.GB12042@gmail.com>
Date:   Thu, 21 Nov 2019 18:08:49 +0100
From:   Ingo Molnar <mingo@...nel.org>
To:     Linus Torvalds <torvalds@...ux-foundation.org>
Cc:     Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        linux-tip-commits@...r.kernel.org,
        Davidlohr Bueso <dbueso@...e.de>,
        Andy Lutomirski <luto@...nel.org>,
        Borislav Petkov <bp@...en8.de>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        "H. Peter Anvin" <hpa@...or.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Rik van Riel <riel@...riel.com>,
        Thomas Gleixner <tglx@...utronix.de>, dave@...olabs.net,
        x86 <x86@...nel.org>
Subject: Re: [tip: x86/mm] x86/mm/pat: Rename pat_rbtree.c to pat_interval.c


* Linus Torvalds <torvalds@...ux-foundation.org> wrote:

> On Wed, Nov 20, 2019, 22:03 tip-bot2 for Davidlohr Bueso <
> tip-bot2@...utronix.de> wrote:
> 
> >
> > x86/mm/pat: Rename pat_rbtree.c to pat_interval.c
> >
> > Considering that we don't use an rbtree but an interval tree,
> > rename the main file accordingly.
> >
> 
> Wouldn't it be even better to not make the same mistake all over again, and
> instead of naming the file by an implementation detail, it should be named
> by what it does?
> 
> Maybe pat_memtype.c or just pat_manage.c or something?
> 
> Or even just pat.c?

Yeah, so incidentally, just before you made this suggestion yesterday, I 
rearranged the files quite a bit in tip:WIP.x86/mm, and the latest naming 
scheme is:

 dagon:~/tip> ls -l arch/x86/mm/pat/
 total 112
 -rw-r--r-- 1 mingo mingo  5782 Nov 21 06:41 cpa-test.c
 -rw-r--r-- 1 mingo mingo   117 Nov 21 06:41 Makefile
 -rw-r--r-- 1 mingo mingo 32026 Nov 21 06:41 memtype.c
 -rw-r--r-- 1 mingo mingo  1470 Nov 21 06:41 memtype.h
 -rw-r--r-- 1 mingo mingo  5003 Nov 21 06:41 memtype_interval.c
 -rw-r--r-- 1 mingo mingo 56668 Nov 21 06:41 set_memory.c

I named most of the files based on the API families they are 
implementing:

 - memtype*.c for the <asm/memtype.h> APIs
 - set_memory.c for the <asm/set_memory.h> APIs.

Is this close to what you had in mind?

 ( Note: cpa-test.c is a leftover that should probably be renamed to 
   set_memory_test.c, with a few explicit set_memory() API tests added as 
   well, not just the internal change_page_attribute() tests. )

I also started the process of tidying up the API namespace which is a bit 
of a historical accident as well, and I'm done with most of the memtype 
funtions, which are now:

            reserve_memtype()               => memtype_reserve()
            free_memtype()                  => memtype_free()
            kernel_map_sync_memtype()       => memtype_kernel_map_sync()
            io_reserve_memtype()            => memtype_reserve_io()
            io_free_memtype()               => memtype_free_io()

            memtype_check_insert()          => memtype_check_insert()
            memtype_erase()                 => memtype_erase()
            memtype_lookup()                => memtype_lookup()
            memtype_copy_nth_element()      => memtype_copy_nth_element()

This work is in WIP.x86/mm:

 git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git WIP.x86/mm

 f53ee099dfac: x86/mm: Tabulate the page table encoding definitions
 2ab1a9a197f7: x86/mm/pat: Fix typo in the Kconfig help text
 0d2a9498e4db: x86/mm/pat: Clean up <asm/memtype.h> externs
 2e2ee215db87: x86/mm/pat: Rename <asm/pat.h> => <asm/memtype.h>
 84285e92bb7a: x86/mm/pat: Standardize on memtype_*() prefix for APIs
 b2c61e70ccca: x86/mm/pat: Move the memtype related files to arch/x86/mm/pat/
 f54b639ad101: x86/mm/pat: Clean up PAT initialization flags
 bca867e88012: x86/mm/pat: Harmonize 'struct memtype *' local variable and function parameter use
 35459848e92f: x86/mm/pat: Simplify the free_memtype() control flow
 a71fbb6061dc: x86/mm/pat: Create fixed width output in /sys/kernel/debug/x86/pat_memtype_list, similar to the E820 debug printouts
 a252a95b6b91: x86/mm/pat: Disambiguate PAT-disabled boot messages
 83d743db88c5: x86/mm/pat: Update the comments in pat.c and pat_interval.c and refresh the code a bit

 820cac65197c: x86/mm/pat: Rename pat_rbtree.c to pat_interval.c
 010ca1041da3: x86/mm/pat: Drop the rbt_ prefix from external memtype calls
 a2cb4c9af315: x86/mm/pat: Do not pass 'rb_root' down the memtype tree helper functions
 2418ac70a9c1: x86/mm/pat: Convert the PAT tree to a generic interval tree

But there's still quite some work left. I'll send out a series once I 
think the end result is a coherent whole.

Davidlohr's four patches are intended for v5.5, the remaining patches 
from me on top of his work will probably need a bit more testing.

Thanks,

	Ingo