From: Michael Neuling <mikey@neuling.org>
To: michael@ellerman.id.au
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
kexec@lists.infradead.org, Anton Blanchard <anton@samba.org>,
linuxppc-dev@ozlabs.org
Subject: Re: [PATCH 2/2] powerpc,kexec: Speedup kexec hpte tear down
Date: Wed, 12 May 2010 09:29:54 +1000 [thread overview]
Message-ID: <30983.1273620594@neuling.org> (raw)
In-Reply-To: <1273561463.9209.138.camel@concordia>
In message <1273561463.9209.138.camel@concordia> you wrote:
>
> --=-S056dRzmrEHDBzKyyTOs
> Content-Type: text/plain; charset="UTF-8"
> Content-Transfer-Encoding: quoted-printable
>
> On Tue, 2010-05-11 at 16:28 +1000, Michael Neuling wrote:
> > Currently for kexec the PTE tear down on 1TB segment systems normally
> > requires 3 hcalls for each PTE removal. On a machine with 32GB of
> > memory it can take around a minute to remove all the PTEs.
> >=20
> ..
> > - /* TODO: Use bulk call */
>
> ...
> > + /* Read in batches of 4,
> > + * invalidate only valid entries not in the VRMA
> > + * hpte_count will be a multiple of 4
> > + */
> > + for (i =3D 0; i < hpte_count; i +=3D 4) {
> > + lpar_rc =3D plpar_pte_read_4_raw(0, i, (void *)ptes);
> > + if (lpar_rc !=3D H_SUCCESS)
> > + continue;
> > + for (j =3D 0; j < 4; j++){
> > + if ((ptes[j].pteh & HPTE_V_VRMA_MASK) =3D=3D
> > + HPTE_V_VRMA_MASK)
> > + continue;
> > + if (ptes[j].pteh & HPTE_V_VALID)
> > + plpar_pte_remove_raw(0, i + j, 0,
> > + &(ptes[j].pteh), &(ptes[j].ptel));
> > }
>
> Have you tried using the bulk remove call, if none of the HPTEs are for
> the VRMA? Rumour was it was slower/the-same, but that may have been
> apocryphal.
No, I didn't try it.
I think the real solution is to ask FW for a new call to do it all for
us.
Mikey
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WARNING: multiple messages have this Message-ID (diff)
From: Michael Neuling <mikey@neuling.org>
To: michael@ellerman.id.au
Cc: kexec@lists.infradead.org, Anton Blanchard <anton@samba.org>,
linuxppc-dev@ozlabs.org
Subject: Re: [PATCH 2/2] powerpc,kexec: Speedup kexec hpte tear down
Date: Wed, 12 May 2010 09:29:54 +1000 [thread overview]
Message-ID: <30983.1273620594@neuling.org> (raw)
In-Reply-To: <1273561463.9209.138.camel@concordia>
In message <1273561463.9209.138.camel@concordia> you wrote:
>
> --=-S056dRzmrEHDBzKyyTOs
> Content-Type: text/plain; charset="UTF-8"
> Content-Transfer-Encoding: quoted-printable
>
> On Tue, 2010-05-11 at 16:28 +1000, Michael Neuling wrote:
> > Currently for kexec the PTE tear down on 1TB segment systems normally
> > requires 3 hcalls for each PTE removal. On a machine with 32GB of
> > memory it can take around a minute to remove all the PTEs.
> >=20
> ..
> > - /* TODO: Use bulk call */
>
> ...
> > + /* Read in batches of 4,
> > + * invalidate only valid entries not in the VRMA
> > + * hpte_count will be a multiple of 4
> > + */
> > + for (i =3D 0; i < hpte_count; i +=3D 4) {
> > + lpar_rc =3D plpar_pte_read_4_raw(0, i, (void *)ptes);
> > + if (lpar_rc !=3D H_SUCCESS)
> > + continue;
> > + for (j =3D 0; j < 4; j++){
> > + if ((ptes[j].pteh & HPTE_V_VRMA_MASK) =3D=3D
> > + HPTE_V_VRMA_MASK)
> > + continue;
> > + if (ptes[j].pteh & HPTE_V_VALID)
> > + plpar_pte_remove_raw(0, i + j, 0,
> > + &(ptes[j].pteh), &(ptes[j].ptel));
> > }
>
> Have you tried using the bulk remove call, if none of the HPTEs are for
> the VRMA? Rumour was it was slower/the-same, but that may have been
> apocryphal.
No, I didn't try it.
I think the real solution is to ask FW for a new call to do it all for
us.
Mikey
next prev parent reply other threads:[~2010-05-11 23:30 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-05-11 6:28 [PATCH 1/2] powerpc: Add hcall to read 4 ptes at a time in real mode Michael Neuling
2010-05-11 6:28 ` Michael Neuling
2010-05-11 6:28 ` [PATCH 2/2] powerpc,kexec: Speedup kexec hpte tear down Michael Neuling
2010-05-11 6:28 ` Michael Neuling
2010-05-11 7:04 ` Michael Ellerman
2010-05-11 7:04 ` Michael Ellerman
2010-05-11 23:29 ` Michael Neuling [this message]
2010-05-11 23:29 ` Michael Neuling
2010-05-12 0:36 ` Michael Ellerman
2010-05-12 0:36 ` Michael Ellerman
2010-05-12 0:43 ` Michael Neuling
2010-05-12 0:43 ` Michael Neuling
2010-05-12 1:00 ` Paul Mackerras
2010-05-12 1:00 ` Paul Mackerras
2010-05-12 1:06 ` Michael Neuling
2010-05-12 1:06 ` Michael Neuling
2010-05-12 1:36 ` Michael Ellerman
2010-05-12 1:36 ` Michael Ellerman
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