From: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
To: maobibo <maobibo@loongson.cn>
Cc: linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] MIPS: Do not flush tlb when setting pmd entry
Date: Mon, 22 Jun 2020 17:48:55 +0200 [thread overview]
Message-ID: <20200622154855.GC17294@alpha.franken.de> (raw)
In-Reply-To: <ea914a82-70c1-b9a3-f6f0-f92a6d6c6e7f@loongson.cn>
On Sat, Jun 20, 2020 at 11:47:35AM +0800, maobibo wrote:
>
>
> On 06/17/2020 07:14 PM, Thomas Bogendoerfer wrote:
> > On Tue, Jun 16, 2020 at 06:34:21PM +0800, maobibo wrote:
> >>
> >>
> >> On 06/15/2020 06:14 PM, Thomas Bogendoerfer wrote:
> >>> On Wed, Jun 03, 2020 at 05:42:13PM +0800, Bibo Mao wrote:
> >>>> Function set_pmd_at is to set pmd entry, if tlb entry need to
> >>>> be flushed, there exists pmdp_huge_clear_flush alike function
> >>>> before set_pmd_at is called. So it is not necessary to call
> >>>> flush_tlb_all in this function.
> >>>
> >>> have you checked all set_pmd_at() calls ? I found a few case where
> >>> it's not clear to me, if tlb flushing is done... If you think this
> >>> is still the right thing to do, please change arch/mips/mm/pgtable-32.c
> >>> as well.
> >> well, I will double check this and do more testing about thp and hugepage.
> >
> > I was more concerned about
> >
> > fs/dax.c
> > fs/proc/task_mmu.c
> > mm/rmap.c
>
> I think that flush_tlb_all should not be called in function set_pmd_at
> on mips platform. However update_mmu_cache_pmd() should be called __after__
> set_pmd_at() function to update tlb entry at some places, it is another issue.
> Here is my analysis in the three files where set_pmd_at is called.
> [..]
thank you for confirming that we are good with removing flush_tlb_all().
Thomas.
--
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea. [ RFC1925, 2.3 ]
next prev parent reply other threads:[~2020-06-22 15:51 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-03 9:42 [PATCH] MIPS: Do not flush tlb when setting pmd entry Bibo Mao
2020-06-15 10:14 ` Thomas Bogendoerfer
2020-06-16 10:34 ` maobibo
2020-06-17 11:14 ` Thomas Bogendoerfer
2020-06-20 3:47 ` maobibo
2020-06-22 15:48 ` Thomas Bogendoerfer [this message]
2020-06-23 6:27 ` maobibo
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=20200622154855.GC17294@alpha.franken.de \
--to=tsbogend@alpha.franken.de \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mips@vger.kernel.org \
--cc=maobibo@loongson.cn \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.