From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Andrea Arcangeli <aarcange@redhat.com>
Cc: "kvm@vger.kernel.org" <kvm@vger.kernel.org>,
Alexander Graf <agraf@suse.de>,
"kvm-ppc@vger.kernel.org" <kvm-ppc@vger.kernel.org>,
Bharat Bhushan <Bharat.Bhushan@freescale.com>,
Scott Wood <scottwood@freescale.com>,
"linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>
Subject: Re: Error in frreing hugepages with preemption enabled
Date: Wed, 04 Dec 2013 13:22:02 +1100 [thread overview]
Message-ID: <1386123722.16703.129.camel@pasglop> (raw)
In-Reply-To: <20131203222121.GB18764@redhat.com>
On Tue, 2013-12-03 at 23:21 +0100, Andrea Arcangeli wrote:
> #ifdef CONFIG_PPC_FSL_BOOK3E
> hugepd_free(tlb, hugepte);
^^^^^^^^^^^^^^^^^^^^^^^^^^
This is the culprit
(Alex, you didn't specify this was embedded or did I miss it ?)
> #else
> pgtable_free_tlb(tlb, hugepte, pdshift - shift);
> #endif
> }
That function does:
batchp = &__get_cpu_var(hugepd_freelist_cur);
IE, it tries to use a per-CPU batch. Basically, it's duplicating the
logic in mm/memory.c for RCU freeing using a per-cpu freelist. I suppose
it assumes being called under something like the page table lock ?
This code also never "flushes" the batch, which is a concern...
Alex, this is Freescale stuff, can you followup with them ?
Cheers,
Ben.
next prev parent reply other threads:[~2013-12-04 2:22 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-29 4:38 Error in frreing hugepages with preemption enabled Bharat Bhushan
2013-11-29 11:13 ` Alexander Graf
2013-12-03 22:21 ` Andrea Arcangeli
2013-12-04 2:22 ` Benjamin Herrenschmidt [this message]
2013-12-05 11:14 ` Bharat Bhushan
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