linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Linus Torvalds <torvalds@linux-foundation.org>
To: Nick Piggin <npiggin@gmail.com>
Cc: linux-mm <linux-mm@kvack.org>,
	ppc-dev <linuxppc-dev@lists.ozlabs.org>,
	linux-arch <linux-arch@vger.kernel.org>,
	"Aneesh Kumar K. V" <aneesh.kumar@linux.vnet.ibm.com>,
	Minchan Kim <minchan@kernel.org>,
	Mel Gorman <mgorman@techsingularity.net>,
	Nadav Amit <nadav.amit@gmail.com>,
	Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [RFC PATCH 3/3] powerpc/64s/radix: optimise TLB flush with precise TLB ranges in mmu_gather
Date: Tue, 12 Jun 2018 11:18:27 -0700	[thread overview]
Message-ID: <CA+55aFzKBieD0Y3sgFQzt+x5esqb9vT6SEQ28xyCz5UWegfFVg@mail.gmail.com> (raw)
In-Reply-To: <20180612071621.26775-4-npiggin@gmail.com>

On Tue, Jun 12, 2018 at 12:16 AM Nicholas Piggin <npiggin@gmail.com> wrote:
>
> This brings the number of tlbiel instructions required by a kernel
> compile from 33M to 25M, most avoided from exec->shift_arg_pages.

And this shows that "page_start/end" is purely for powerpc and used
nowhere else.

The previous patch should have been to purely powerpc page table
walking and not touch asm-generic/tlb.h

I think you should make those changes to
arch/powerpc/include/asm/tlb.h. If that means you can't use the
generic header, then so be it.

Or maybe you can embed the generic case in some ppc-specific
structures, and use 90% of the generic code just with your added
wrappers for that radix invalidation on top.

But don't make other architectures do pointless work that doesn't
matter - or make sense - for them.

               Linus

  reply	other threads:[~2018-06-12 18:18 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-06-12  7:16 [RFC PATCH 0/3] couple of TLB flush optimisations Nicholas Piggin
2018-06-12  7:16 ` [RFC PATCH 1/3] Revert "mm: always flush VMA ranges affected by zap_page_range" Nicholas Piggin
2018-06-12 13:53   ` Aneesh Kumar K.V
2018-06-12 18:52   ` Nadav Amit
2018-06-12  7:16 ` [RFC PATCH 2/3] mm: mmu_gather track of invalidated TLB ranges explicitly for more precise flushing Nicholas Piggin
2018-06-12 18:14   ` Linus Torvalds
2018-06-12  7:16 ` [RFC PATCH 3/3] powerpc/64s/radix: optimise TLB flush with precise TLB ranges in mmu_gather Nicholas Piggin
2018-06-12 18:18   ` Linus Torvalds [this message]
2018-06-12 22:31     ` Nicholas Piggin
2018-06-12 22:42       ` Linus Torvalds
2018-06-12 23:09         ` Nicholas Piggin
2018-06-12 23:26           ` Linus Torvalds
2018-06-12 23:39             ` Linus Torvalds
2018-06-13  0:12               ` Nicholas Piggin
2018-06-13  1:10                 ` Linus Torvalds
2018-06-14  2:49                   ` Nicholas Piggin
2018-06-14  6:15                     ` Linus Torvalds
2018-06-14  6:51                       ` Nicholas Piggin
2018-06-12 23:53             ` Nicholas Piggin

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=CA+55aFzKBieD0Y3sgFQzt+x5esqb9vT6SEQ28xyCz5UWegfFVg@mail.gmail.com \
    --to=torvalds@linux-foundation.org \
    --cc=akpm@linux-foundation.org \
    --cc=aneesh.kumar@linux.vnet.ibm.com \
    --cc=linux-arch@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=linuxppc-dev@lists.ozlabs.org \
    --cc=mgorman@techsingularity.net \
    --cc=minchan@kernel.org \
    --cc=nadav.amit@gmail.com \
    --cc=npiggin@gmail.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