This patch adds a special file /sys/kernel/debug/powerpc/pft-size
which can be used to view the current size of the hash page table (as
a bit shift) and to trigger a resize of the hash table on PAPR guests.
Signed-off-by: David Gibson <da...@gibson.dropbear.id.au>
---
arch/powerpc/platforms/pseries/lpar.c | 26 ++++++++++++++++++++++++++
1 file changed, 26 insertions(+)
diff --git a/arch/powerpc/platforms/pseries/lpar.c
b/arch/powerpc/platforms/pseries/lpar.c
index f6e7af5..dba9644 100644
--- a/arch/powerpc/platforms/pseries/lpar.c
+++ b/arch/powerpc/platforms/pseries/lpar.c
@@ -29,6 +29,7 @@
#include <linux/jump_label.h>
#include <linux/delay.h>
#include <linux/stop_machine.h>
+#include <linux/debugfs.h>
#include <asm/processor.h>
#include <asm/mmu.h>
#include <asm/page.h>
@@ -903,3 +904,28 @@ int pseries_lpar_resize_hpt(unsigned long shift)
return 0;
}
+
+static int ppc64_pft_size_get(void *data, u64 *val)
+{
+ *val = ppc64_pft_size;
+ return 0;
+}
+
+static int ppc64_pft_size_set(void *data, u64 val)
+{
+ return pseries_lpar_resize_hpt(val);
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(fops_ppc64_pft_size,
+ ppc64_pft_size_get, ppc64_pft_size_set, "%llu\n");
+
+static int __init pseries_lpar_debugfs(void)
+{
+ if (!debugfs_create_file("pft-size", 0600, powerpc_debugfs_root,
+ NULL, &fops_ppc64_pft_size)) {
+ pr_err("lpar: unable to create ppc64_pft_size debugsfs file\n");
+ }
+
+ return 0;
+}
+machine_device_initcall(pseries, pseries_lpar_debugfs);
--
2.5.0
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