From: Lance Yang <ioworker0@gmail.com>
To: Ryan Roberts <ryan.roberts@arm.com>
Cc: Bang Li <libang.li@antgroup.com>,
akpm@linux-foundation.org, chenhuacai@kernel.org,
tsbogend@alpha.franken.de, paul.walmsley@sifive.com,
palmer@dabbelt.com, chris@zankel.net, jcmvbkbc@gmail.com,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
loongarch@lists.linux.dev, linux-riscv@lists.infradead.org,
david@redhat.com, libang.linux@gmail.com
Subject: Re: [PATCH v2 5/5] mm: Add update_mmu_tlb_range()
Date: Fri, 10 May 2024 17:19:12 +0800 [thread overview]
Message-ID: <CAK1f24mNZ5=HubBNcnuabzWAEqAALnnKVd3N9D5+jNBjxO6p+w@mail.gmail.com> (raw)
In-Reply-To: <eb41fcb3-7207-40a8-9b49-0825a2e74e86@arm.com>
On Fri, May 10, 2024 at 5:05 PM Ryan Roberts <ryan.roberts@arm.com> wrote:
>
> On 06/05/2024 16:51, Bang Li wrote:
> > After the commit 19eaf44954df ("mm: thp: support allocation of anonymous
> > multi-size THP"), it may need to batch update tlb of an address range
> > through the update_mmu_tlb function. We can simplify this operation by
> > adding the update_mmu_tlb_range function, which may also reduce the
> > execution of some unnecessary code in some architectures.
> >
> > Signed-off-by: Bang Li <libang.li@antgroup.com>
> > ---
> > include/linux/pgtable.h | 8 ++++++++
> > mm/memory.c | 4 +---
> > 2 files changed, 9 insertions(+), 3 deletions(-)
> >
> > diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
> > index 18019f037bae..869bfe6054f1 100644
> > --- a/include/linux/pgtable.h
> > +++ b/include/linux/pgtable.h
> > @@ -737,6 +737,14 @@ static inline void update_mmu_tlb(struct vm_area_struct *vma,
> > #define __HAVE_ARCH_UPDATE_MMU_TLB
> > #endif
>
> Given you are implementing update_mmu_tlb_range() in all the arches that
> currently override update_mmu_tlb() I wonder if it would be cleaner to remove
> update_mmu_tlb() from all those arches, and define generically, removing the
> ability for arches to override it:
Sounds great! Let's get it done.
>
> static inline void update_mmu_tlb(struct vm_area_struct *vma,
> unsigned long address, pte_t *ptep)
> {
> update_mmu_tlb_range(vma, address, ptep, 1);
> }
>
> >
> > +#ifndef __HAVE_ARCH_UPDATE_MMU_TLB_RANGE
> > +static inline void update_mmu_tlb_range(struct vm_area_struct *vma,
> > + unsigned long address, pte_t *ptep, unsigned int nr)
> > +{
> > +}
> > +#define __HAVE_ARCH_UPDATE_MMU_TLB_RANGE
> > +#endif
>
> Then you could use the modern override scheme as Lance suggested and you won't
> have any confusion with __HAVE_ARCH_UPDATE_MMU_TLB because it won't exist anymore.
+1. It might be better to use the modern override scheme :)
Thanks,
Lance
>
> > +
> > /*
> > * Some architectures may be able to avoid expensive synchronization
> > * primitives when modifications are made to PTE's which are already
> > diff --git a/mm/memory.c b/mm/memory.c
> > index eea6e4984eae..2d53e29cf76e 100644
> > --- a/mm/memory.c
> > +++ b/mm/memory.c
> > @@ -4421,7 +4421,6 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf)
> > vm_fault_t ret = 0;
> > int nr_pages = 1;
> > pte_t entry;
> > - int i;
> >
> > /* File mapping without ->vm_ops ? */
> > if (vma->vm_flags & VM_SHARED)
> > @@ -4491,8 +4490,7 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf)
> > update_mmu_tlb(vma, addr, vmf->pte);
> > goto release;
> > } else if (nr_pages > 1 && !pte_range_none(vmf->pte, nr_pages)) {
> > - for (i = 0; i < nr_pages; i++)
> > - update_mmu_tlb(vma, addr + PAGE_SIZE * i, vmf->pte + i);
> > + update_mmu_tlb_range(vma, addr, vmf->pte, nr_pages);
>
> I certainly agree that this will be a useful helper to have. I expect there will
> be more users in future.
>
> > goto release;
> > }
> >
>
next prev parent reply other threads:[~2024-05-10 9:19 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-06 15:51 [PATCH v2 0/5] Add update_mmu_tlb_range() to simplify code Bang Li
2024-05-06 15:51 ` [PATCH v2 1/5] LoongArch: Add update_mmu_tlb_range() Bang Li
2024-05-06 15:51 ` [PATCH v2 2/5] mips: " Bang Li
2024-05-06 15:51 ` [PATCH v2 3/5] riscv: " Bang Li
2024-05-07 5:35 ` Alexandre Ghiti
2024-05-10 2:18 ` Bang Li
2024-05-06 15:51 ` [PATCH v2 4/5] xtensa: " Bang Li
2024-05-06 15:51 ` [PATCH v2 5/5] mm: " Bang Li
2024-05-06 16:07 ` Lance Yang
2024-05-07 3:26 ` Bang Li
2024-05-10 9:05 ` Ryan Roberts
2024-05-10 9:19 ` Lance Yang [this message]
2024-05-10 16:36 ` Bang Li
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='CAK1f24mNZ5=HubBNcnuabzWAEqAALnnKVd3N9D5+jNBjxO6p+w@mail.gmail.com' \
--to=ioworker0@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=chenhuacai@kernel.org \
--cc=chris@zankel.net \
--cc=david@redhat.com \
--cc=jcmvbkbc@gmail.com \
--cc=libang.li@antgroup.com \
--cc=libang.linux@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-riscv@lists.infradead.org \
--cc=loongarch@lists.linux.dev \
--cc=palmer@dabbelt.com \
--cc=paul.walmsley@sifive.com \
--cc=ryan.roberts@arm.com \
--cc=tsbogend@alpha.franken.de \
/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).