[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <c08d81286b9986c086e9b68e3440f9bf99086d70.camel@redhat.com>
Date: Thu, 22 Jun 2023 16:57:39 +0300
From: ypodemsk@...hat.com
To: Nadav Amit <nadav.amit@...il.com>
Cc: mtosatti@...hat.com, ppandit@...hat.com,
David Hildenbrand <david@...hat.com>,
"Russell King (Oracle)" <linux@...linux.org.uk>,
Michael Ellerman <mpe@...erman.id.au>,
Nicholas Piggin <npiggin@...il.com>,
Christophe Leroy <christophe.leroy@...roup.eu>,
Heiko Carstens <hca@...ux.ibm.com>, gor@...ux.ibm.com,
agordeev@...ux.ibm.com,
Christian Borntraeger <borntraeger@...ux.ibm.com>,
svens@...ux.ibm.com, "David S. Miller" <davem@...emloft.net>,
Thomas Gleixner <tglx@...utronix.de>,
Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
Dave Hansen <dave.hansen@...ux.intel.com>,
"H. Peter Anvin" <hpa@...or.com>,
Kees Cook <keescook@...omium.org>,
"Paul E. McKenney" <paulmck@...nel.org>, frederic@...nel.org,
Will Deacon <will@...nel.org>,
Peter Zijlstra <peterz@...radead.org>, ardb@...nel.org,
samitolvanen@...gle.com, juerg.haefliger@...onical.com,
Arnd Bergmann <arnd@...db.de>, rmk+kernel@...linux.org.uk,
geert+renesas@...der.be, linus.walleij@...aro.org,
Andrew Morton <akpm@...ux-foundation.org>,
sebastian.reichel@...labora.com, Mike Rapoport <rppt@...nel.org>,
aneesh.kumar@...ux.ibm.com,
the arch/x86 maintainers <x86@...nel.org>,
linux-arm-kernel@...ts.infradead.org,
linuxppc-dev <linuxppc-dev@...ts.ozlabs.org>,
linux-s390 <linux-s390@...r.kernel.org>,
sparclinux@...r.kernel.org, linux-arch@...r.kernel.org,
linux-mm <linux-mm@...ck.org>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 2/2] mm/mmu_gather: send tlb_remove_table_smp_sync
IPI only to MM CPUs
On Wed, 2023-06-21 at 11:02 -0700, Nadav Amit wrote:
> > On Jun 20, 2023, at 7:46 AM, Yair Podemsky <ypodemsk@...hat.com>
> > wrote:
> >
> > @@ -1525,7 +1525,7 @@ static void collapse_and_free_pmd(struct
> > mm_struct *mm, struct vm_area_struct *v
> > addr + HPAGE_PMD_SIZE);
> > mmu_notifier_invalidate_range_start(&range);
> > pmd = pmdp_collapse_flush(vma, addr, pmdp);
> > - tlb_remove_table_sync_one();
> > + tlb_remove_table_sync_one(mm);
>
> Can’t pmdp_collapse_flush() have one additional argument
> “freed_tables”
> that it would propagate, for instance on x86 to flush_tlb_mm_range()
> ?
> Then you would not need tlb_remove_table_sync_one() to issue an
> additional
> IPI, no?
>
> It just seems that you might still have 2 IPIs in many cases instead
> of
> one, and unless I am missing something, I don’t see why.
>
Hi Nadav,
Thanks for your comment.
I think you are right and in some configurations 2 IPIs might occur.
However I a am not really dealing with the thp code at the moment,
This patch is about the mmu_gatherer and mostly dealing with IPIs sent
via the other code path.
Thanks,
Yair
Powered by blists - more mailing lists