* [PATCH] powerpc/pseries: Use H_CLEAR_HPT to clear MMU hash table during kexec
@ 2016-10-01 10:41 Anton Blanchard
2016-10-27 6:26 ` Mahesh Jagannath Salgaonkar
2016-11-14 12:17 ` Michael Ellerman
0 siblings, 2 replies; 3+ messages in thread
From: Anton Blanchard @ 2016-10-01 10:41 UTC (permalink / raw)
To: benh, paulus, mpe, mahesh, srikar, hbathini; +Cc: linuxppc-dev
From: Anton Blanchard <anton@samba.org>
An hcall was recently added that does exactly what we need
during kexec - it clears the entire MMU hash table, ignoring any
VRMA mappings.
Try it and fall back to the old method if we get a failure.
On a POWER8 box with 5TB of memory, this reduces the time it takes to
kexec a new kernel from from 4 minutes to 1 minute.
Signed-off-by: Anton Blanchard <anton@samba.org>
---
arch/powerpc/include/asm/hvcall.h | 3 ++-
arch/powerpc/platforms/pseries/lpar.c | 14 +++++++++++++-
2 files changed, 15 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/include/asm/hvcall.h b/arch/powerpc/include/asm/hvcall.h
index 708edeb..489748e 100644
--- a/arch/powerpc/include/asm/hvcall.h
+++ b/arch/powerpc/include/asm/hvcall.h
@@ -275,7 +275,8 @@
#define H_COP 0x304
#define H_GET_MPP_X 0x314
#define H_SET_MODE 0x31C
-#define MAX_HCALL_OPCODE H_SET_MODE
+#define H_CLEAR_HPT 0x358
+#define MAX_HCALL_OPCODE H_CLEAR_HPT
/* H_VIOCTL functions */
#define H_GET_VIOA_DUMP_SIZE 0x01
diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c
index 86707e6..03884a8 100644
--- a/arch/powerpc/platforms/pseries/lpar.c
+++ b/arch/powerpc/platforms/pseries/lpar.c
@@ -221,7 +221,7 @@ static long pSeries_lpar_hpte_remove(unsigned long hpte_group)
return -1;
}
-static void pSeries_lpar_hptab_clear(void)
+static void __pSeries_lpar_clear_hpt(void)
{
unsigned long size_bytes = 1UL << ppc64_pft_size;
unsigned long hpte_count = size_bytes >> 4;
@@ -249,6 +249,18 @@ static void pSeries_lpar_hptab_clear(void)
&(ptes[j].pteh), &(ptes[j].ptel));
}
}
+}
+
+static void pSeries_lpar_hptab_clear(void)
+{
+ int rc;
+
+ do {
+ rc = plpar_hcall_norets(H_CLEAR_HPT);
+ } while (rc == H_CONTINUE);
+
+ if (rc != H_SUCCESS)
+ __pSeries_lpar_clear_hpt();
#ifdef __LITTLE_ENDIAN__
/*
--
2.7.4
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] powerpc/pseries: Use H_CLEAR_HPT to clear MMU hash table during kexec
2016-10-01 10:41 [PATCH] powerpc/pseries: Use H_CLEAR_HPT to clear MMU hash table during kexec Anton Blanchard
@ 2016-10-27 6:26 ` Mahesh Jagannath Salgaonkar
2016-11-14 12:17 ` Michael Ellerman
1 sibling, 0 replies; 3+ messages in thread
From: Mahesh Jagannath Salgaonkar @ 2016-10-27 6:26 UTC (permalink / raw)
To: Anton Blanchard, benh, paulus, mpe, srikar, hbathini; +Cc: linuxppc-dev
On 10/01/2016 04:11 PM, Anton Blanchard wrote:
> From: Anton Blanchard <anton@samba.org>
>
> An hcall was recently added that does exactly what we need
> during kexec - it clears the entire MMU hash table, ignoring any
> VRMA mappings.
>
> Try it and fall back to the old method if we get a failure.
>
> On a POWER8 box with 5TB of memory, this reduces the time it takes to
> kexec a new kernel from from 4 minutes to 1 minute.
>
> Signed-off-by: Anton Blanchard <anton@samba.org>
Tested-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
> ---
> arch/powerpc/include/asm/hvcall.h | 3 ++-
> arch/powerpc/platforms/pseries/lpar.c | 14 +++++++++++++-
> 2 files changed, 15 insertions(+), 2 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/hvcall.h b/arch/powerpc/include/asm/hvcall.h
> index 708edeb..489748e 100644
> --- a/arch/powerpc/include/asm/hvcall.h
> +++ b/arch/powerpc/include/asm/hvcall.h
> @@ -275,7 +275,8 @@
> #define H_COP 0x304
> #define H_GET_MPP_X 0x314
> #define H_SET_MODE 0x31C
> -#define MAX_HCALL_OPCODE H_SET_MODE
> +#define H_CLEAR_HPT 0x358
> +#define MAX_HCALL_OPCODE H_CLEAR_HPT
>
> /* H_VIOCTL functions */
> #define H_GET_VIOA_DUMP_SIZE 0x01
> diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c
> index 86707e6..03884a8 100644
> --- a/arch/powerpc/platforms/pseries/lpar.c
> +++ b/arch/powerpc/platforms/pseries/lpar.c
> @@ -221,7 +221,7 @@ static long pSeries_lpar_hpte_remove(unsigned long hpte_group)
> return -1;
> }
>
> -static void pSeries_lpar_hptab_clear(void)
> +static void __pSeries_lpar_clear_hpt(void)
> {
> unsigned long size_bytes = 1UL << ppc64_pft_size;
> unsigned long hpte_count = size_bytes >> 4;
> @@ -249,6 +249,18 @@ static void pSeries_lpar_hptab_clear(void)
> &(ptes[j].pteh), &(ptes[j].ptel));
> }
> }
> +}
> +
> +static void pSeries_lpar_hptab_clear(void)
> +{
> + int rc;
> +
> + do {
> + rc = plpar_hcall_norets(H_CLEAR_HPT);
> + } while (rc == H_CONTINUE);
> +
> + if (rc != H_SUCCESS)
> + __pSeries_lpar_clear_hpt();
>
> #ifdef __LITTLE_ENDIAN__
> /*
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: powerpc/pseries: Use H_CLEAR_HPT to clear MMU hash table during kexec
2016-10-01 10:41 [PATCH] powerpc/pseries: Use H_CLEAR_HPT to clear MMU hash table during kexec Anton Blanchard
2016-10-27 6:26 ` Mahesh Jagannath Salgaonkar
@ 2016-11-14 12:17 ` Michael Ellerman
1 sibling, 0 replies; 3+ messages in thread
From: Michael Ellerman @ 2016-11-14 12:17 UTC (permalink / raw)
To: Anton Blanchard, benh, paulus, mahesh, srikar, hbathini; +Cc: linuxppc-dev
On Sat, 2016-01-10 at 10:41:56 UTC, Anton Blanchard wrote:
> From: Anton Blanchard <anton@samba.org>
>
> An hcall was recently added that does exactly what we need
> during kexec - it clears the entire MMU hash table, ignoring any
> VRMA mappings.
>
> Try it and fall back to the old method if we get a failure.
>
> On a POWER8 box with 5TB of memory, this reduces the time it takes to
> kexec a new kernel from from 4 minutes to 1 minute.
>
> Signed-off-by: Anton Blanchard <anton@samba.org>
Applied to powerpc next, thanks.
https://git.kernel.org/powerpc/c/5246adec59458b5d325b8e1462ea9e
cheers
^ permalink raw reply [flat|nested] 3+ messages in thread
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2016-10-01 10:41 [PATCH] powerpc/pseries: Use H_CLEAR_HPT to clear MMU hash table during kexec Anton Blanchard
2016-10-27 6:26 ` Mahesh Jagannath Salgaonkar
2016-11-14 12:17 ` Michael Ellerman
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