From: Anton Blanchard <an...@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 <an...@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
