From: Balbir Singh <bsingharora@gmail.com>
To: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>,
benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au,
akpm@linux-foundation.org,
Mel Gorman <mgorman@techsingularity.net>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: linuxppc-dev@lists.ozlabs.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH V3] powerpc/mm: Fix Multi hit ERAT cause by recent THP update
Date: Mon, 15 Feb 2016 16:09:57 +1100 [thread overview]
Message-ID: <1455512997.16012.24.camel@gmail.com> (raw)
In-Reply-To: <87lh6mfv2j.fsf@linux.vnet.ibm.com>
> Now we can't depend for mm_cpumask, a parallel find_linux_pte_hugepte
> can happen outside that. Now i had a variant for kick_all_cpus_sync that
> ignored idle cpus. But then that needs more verification.
>
> http://article.gmane.org/gmane.linux.ports.ppc.embedded/81105
Can be racy as a CPU moves from non-idle to idle
In
> + pmd_hugepage_update(vma->vm_mm, address, pmdp, ~0UL, 0);
> + /*
> + * This ensures that generic code that rely on IRQ disabling
> + * to prevent a parallel THP split work as expected.
> + */
> + kick_all_cpus_sync();
pmdp_invalidate()->pmd_hugepage_update() can still run in parallel with
find_linux_pte_or_hugepte() and race.. Am I missing something?
Balbir Singh
WARNING: multiple messages have this Message-ID (diff)
From: Balbir Singh <bsingharora@gmail.com>
To: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>,
benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au,
akpm@linux-foundation.org,
Mel Gorman <mgorman@techsingularity.net>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: linuxppc-dev@lists.ozlabs.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH V3] powerpc/mm: Fix Multi hit ERAT cause by recent THP update
Date: Mon, 15 Feb 2016 16:09:57 +1100 [thread overview]
Message-ID: <1455512997.16012.24.camel@gmail.com> (raw)
In-Reply-To: <87lh6mfv2j.fsf@linux.vnet.ibm.com>
> Now we can't depend for mm_cpumask, a parallel find_linux_pte_hugepte
> can happen outside that. Now i had a variant for kick_all_cpus_sync that
> ignored idle cpus. But then that needs more verification.
>
> http://article.gmane.org/gmane.linux.ports.ppc.embedded/81105
Can be racy as a CPU moves from non-idle to idle
In
> +A A A A A pmd_hugepage_update(vma->vm_mm, address, pmdp, ~0UL, 0);
> +A A A A A /*
> +A A A A A A * This ensures that generic code that rely on IRQ disabling
> +A A A A A A * to prevent a parallel THP split work as expected.
> +A A A A A A */
> +A A A A A kick_all_cpus_sync();
pmdp_invalidate()->pmd_hugepage_update() can still run in parallel withA
find_linux_pte_or_hugepte() and race.. Am I missing something?
Balbir Singh
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2016-02-15 5:10 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-09 1:20 [PATCH V3] powerpc/mm: Fix Multi hit ERAT cause by recent THP update Aneesh Kumar K.V
2016-02-09 1:20 ` Aneesh Kumar K.V
2016-02-09 12:16 ` [V3] " Michael Ellerman
2016-02-09 12:16 ` Michael Ellerman
2016-02-14 5:32 ` Aneesh Kumar K.V
2016-02-14 5:32 ` Aneesh Kumar K.V
2016-02-15 2:44 ` [PATCH V3] " Balbir Singh
2016-02-15 2:44 ` Balbir Singh
2016-02-15 4:37 ` Aneesh Kumar K.V
2016-02-15 4:37 ` Aneesh Kumar K.V
2016-02-15 4:37 ` Aneesh Kumar K.V
2016-02-15 5:09 ` Balbir Singh [this message]
2016-02-15 5:09 ` Balbir Singh
2016-02-15 11:01 ` Aneesh Kumar K.V
2016-02-15 11:01 ` Aneesh Kumar K.V
2016-02-15 11:01 ` Aneesh Kumar K.V
2016-02-16 5:20 ` Balbir Singh
2016-02-16 5:20 ` Balbir Singh
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=1455512997.16012.24.camel@gmail.com \
--to=bsingharora@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=aneesh.kumar@linux.vnet.ibm.com \
--cc=benh@kernel.crashing.org \
--cc=kirill.shutemov@linux.intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=mgorman@techsingularity.net \
--cc=mpe@ellerman.id.au \
--cc=paulus@samba.org \
/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.