From: "Kirill A. Shutemov" <kirill@shutemov.name>
To: Ingo Molnar <mingo@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>,
linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>,
Vlastimil Babka <vbabka@suse.cz>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Thomas Gleixner <tglx@linutronix.de>,
Mike Rapoport <rppt@linux.vnet.ibm.com>,
Jason Gunthorpe <jgg@ziepe.ca>,
Dan Williams <dan.j.williams@intel.com>,
Peter Zijlstra <peterz@infradead.org>,
Michal Hocko <mhocko@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Mark Brown <broonie@kernel.org>,
Steven Price <Steven.Price@arm.com>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Masahiro Yamada <yamada.masahiro@socionext.com>,
Kees Cook <keescook@chromium.org>,
Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>,
Matthew Wilcox <willy@infradead.org>,
Sri Krishna chowdary <schowdary@nvidia.com>,
Dave Hansen <dave.hansen@intel.com>,
Russell King - ARM Linux <linux@armlinux.org.uk>,
Michael Ellerman <mpe@ellerman.id.au>,
Paul Mackerras <paulus@samba.org>,
Martin Schwidefsky <schwidefsky@de.ibm.com>,
Heiko Carstens <heiko.carstens@de.ibm.com>,
"David S. Miller" <davem@davemloft.net>,
Vineet Gupta <vgupta@synopsys.com>,
James Hogan <jhogan@kernel.org>,
Paul Burton <paul.burton@mips.com>,
Ralf Baechle <ralf@linux-mips.org>,
Gerald Schaefer <gerald.schaefer@de.ibm.com>,
Christophe Leroy <christophe.leroy@c-s.fr>,
linux-snps-arc@lists.infradead.org, linux-mips@vger.kernel.org,
linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org,
linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org,
linux-sh@vger.kernel.org, sparclinux@vger.kernel.org,
x86@kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH V4 2/2] mm/pgtable/debug: Add test validating architecture page table helpers
Date: Mon, 7 Oct 2019 17:00:58 +0300 [thread overview]
Message-ID: <20191007140058.um5g44rvxyzyiref@box> (raw)
In-Reply-To: <20191007135158.GA36360@gmail.com>
On Mon, Oct 07, 2019 at 03:51:58PM +0200, Ingo Molnar wrote:
>
> * Kirill A. Shutemov <kirill@shutemov.name> wrote:
>
> > On Mon, Oct 07, 2019 at 03:06:17PM +0200, Ingo Molnar wrote:
> > >
> > > * Anshuman Khandual <anshuman.khandual@arm.com> wrote:
> > >
> > > > This adds a test module which will validate architecture page table helpers
> > > > and accessors regarding compliance with generic MM semantics expectations.
> > > > This will help various architectures in validating changes to the existing
> > > > page table helpers or addition of new ones.
> > > >
> > > > Test page table and memory pages creating it's entries at various level are
> > > > all allocated from system memory with required alignments. If memory pages
> > > > with required size and alignment could not be allocated, then all depending
> > > > individual tests are skipped.
> > >
> > > > diff --git a/arch/x86/include/asm/pgtable_64_types.h b/arch/x86/include/asm/pgtable_64_types.h
> > > > index 52e5f5f2240d..b882792a3999 100644
> > > > --- a/arch/x86/include/asm/pgtable_64_types.h
> > > > +++ b/arch/x86/include/asm/pgtable_64_types.h
> > > > @@ -40,6 +40,8 @@ static inline bool pgtable_l5_enabled(void)
> > > > #define pgtable_l5_enabled() 0
> > > > #endif /* CONFIG_X86_5LEVEL */
> > > >
> > > > +#define mm_p4d_folded(mm) (!pgtable_l5_enabled())
> > > > +
> > > > extern unsigned int pgdir_shift;
> > > > extern unsigned int ptrs_per_p4d;
> > >
> > > Any deep reason this has to be a macro instead of proper C?
> >
> > It's a way to override the generic mm_p4d_folded(). It can be rewritten
> > as inline function + define. Something like:
> >
> > #define mm_p4d_folded mm_p4d_folded
> > static inline bool mm_p4d_folded(struct mm_struct *mm)
> > {
> > return !pgtable_l5_enabled();
> > }
> >
> > But I don't see much reason to be more verbose here than needed.
>
> C type checking? Documentation? Yeah, I know it's just a one-liner, but
> the principle of the death by a thousand cuts applies here.
Okay, if you think it worth it. Anshuman, could you fix it up for the next
submission?
> BTW., any reason this must be in the low level pgtable_64_types.h type
> header, instead of one of the API level header files?
I defined it next pgtable_l5_enabled(). What is more appropriate place to
you? pgtable_64.h? Yeah, it makes sense.
--
Kirill A. Shutemov
next prev parent reply other threads:[~2019-10-07 14:01 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-07 5:45 [PATCH V4 0/2] mm/debug: Add tests for architecture exported page table helpers Anshuman Khandual
2019-10-07 5:45 ` [PATCH V4 1/2] mm/hugetlb: Make alloc_gigantic_page() available for general use Anshuman Khandual
2019-10-07 5:45 ` [PATCH V4 2/2] mm/pgtable/debug: Add test validating architecture page table helpers Anshuman Khandual
2019-10-07 13:06 ` Ingo Molnar
2019-10-07 13:26 ` Kirill A. Shutemov
2019-10-07 13:51 ` Ingo Molnar
2019-10-07 14:00 ` Kirill A. Shutemov [this message]
2019-10-08 8:13 ` Anshuman Khandual
2019-10-08 8:07 ` Anshuman Khandual
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20191007140058.um5g44rvxyzyiref@box \
--to=kirill@shutemov.name \
--cc=Steven.Price@arm.com \
--cc=akpm@linux-foundation.org \
--cc=anshuman.khandual@arm.com \
--cc=ard.biesheuvel@linaro.org \
--cc=broonie@kernel.org \
--cc=christophe.leroy@c-s.fr \
--cc=dan.j.williams@intel.com \
--cc=dave.hansen@intel.com \
--cc=davem@davemloft.net \
--cc=gerald.schaefer@de.ibm.com \
--cc=gregkh@linuxfoundation.org \
--cc=heiko.carstens@de.ibm.com \
--cc=jgg@ziepe.ca \
--cc=jhogan@kernel.org \
--cc=keescook@chromium.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-ia64@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mips@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-s390@vger.kernel.org \
--cc=linux-sh@vger.kernel.org \
--cc=linux-snps-arc@lists.infradead.org \
--cc=linux@armlinux.org.uk \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=mark.rutland@arm.com \
--cc=mhocko@kernel.org \
--cc=mingo@kernel.org \
--cc=mpe@ellerman.id.au \
--cc=paul.burton@mips.com \
--cc=paulus@samba.org \
--cc=penguin-kernel@i-love.sakura.ne.jp \
--cc=peterz@infradead.org \
--cc=ralf@linux-mips.org \
--cc=rppt@linux.vnet.ibm.com \
--cc=schowdary@nvidia.com \
--cc=schwidefsky@de.ibm.com \
--cc=sparclinux@vger.kernel.org \
--cc=tglx@linutronix.de \
--cc=vbabka@suse.cz \
--cc=vgupta@synopsys.com \
--cc=willy@infradead.org \
--cc=x86@kernel.org \
--cc=yamada.masahiro@socionext.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).