From: Martin Hicks <mort@sgi.com>
This adds a syscall to call into the reclaim code. The use for this would be
to clear all unneeded pagecache and slabcache off a node before running a big
HPC job.
A "memory freer" app can be found at:
http://www.bork.org/~mort/sgi/localreclaim/reclaim_memory.c
Signed-off-by: Martin Hicks <mort@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
arch/ia64/kernel/entry.S | 6 ++---
kernel/sys_ni.c | 2 +
mm/vmscan.c | 52 +++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 57 insertions(+), 3 deletions(-)
diff -puN arch/ia64/kernel/entry.S~vm-reclaim_page_cache_node-syscall arch/ia64/kernel/entry.S
--- 25/arch/ia64/kernel/entry.S~vm-reclaim_page_cache_node-syscall 2005-05-03 16:14:03.000000000 -0700
+++ 25-akpm/arch/ia64/kernel/entry.S 2005-05-03 16:14:03.000000000 -0700
@@ -1571,9 +1571,9 @@ sys_call_table:
data8 sys_add_key
data8 sys_request_key
data8 sys_keyctl
- data8 sys_ni_syscall
- data8 sys_ni_syscall // 1275
- data8 sys_ni_syscall
+ data8 sys_ni_syscall // reserved for sys_ioprio_set
+ data8 sys_ni_syscall // reserved for sys_ioprio_get 1275
+ data8 sys_reclaim_page_cache_node
data8 sys_ni_syscall
data8 sys_ni_syscall
data8 sys_ni_syscall
diff -puN kernel/sys_ni.c~vm-reclaim_page_cache_node-syscall kernel/sys_ni.c
--- 25/kernel/sys_ni.c~vm-reclaim_page_cache_node-syscall 2005-05-03 16:14:03.000000000 -0700
+++ 25-akpm/kernel/sys_ni.c 2005-05-03 16:14:03.000000000 -0700
@@ -77,6 +77,8 @@ cond_syscall(sys_request_key);
cond_syscall(sys_keyctl);
cond_syscall(compat_sys_keyctl);
cond_syscall(compat_sys_socketcall);
+cond_syscall(sys_reclaim_page_cache_node);
+cond_syscall(compat_sys_reclaim_page_cache_node);
/* arch-specific weak syscall entries */
cond_syscall(sys_pciconfig_read);
diff -puN mm/vmscan.c~vm-reclaim_page_cache_node-syscall mm/vmscan.c
--- 25/mm/vmscan.c~vm-reclaim_page_cache_node-syscall 2005-05-03 16:14:03.000000000 -0700
+++ 25-akpm/mm/vmscan.c 2005-05-03 16:14:03.000000000 -0700
@@ -33,6 +33,7 @@
#include <linux/cpuset.h>
#include <linux/notifier.h>
#include <linux/rwsem.h>
+#include <linux/compat.h>
#include <asm/tlbflush.h>
#include <asm/div64.h>
@@ -1505,3 +1506,54 @@ unsigned int reclaim_clean_pages(struct
return total_reclaimed;
}
+
+
+/* Free some page cache on a specified node */
+asmlinkage long sys_reclaim_page_cache_node(unsigned int node,
+ unsigned long bytes,
+ unsigned int flags)
+{
+ unsigned long pages_to_reclaim;
+ unsigned long reclaimed = 0;
+ int i;
+ struct zone *z, **zones;
+
+ if (!node_online(node))
+ /* get a better error code here? */
+ return -EINVAL;
+
+ /* Check to make sure that we have reasonable flag values */
+ if (flags & RECLAIM_MASK)
+ return -EINVAL;
+
+ /* Set the Manual reclaim flag to override rate limiting */
+ flags |= RECLAIM_MANUAL;
+
+ pages_to_reclaim = (bytes + PAGE_SIZE - 1)/PAGE_SIZE;
+
+ /*
+ * This is kind of bad because we're using zone internals.
+ * The goal here is to start reclaiming from the "higest" zone,
+ * ZONE_HIGHMEM -> ZONE_NORMAL -> ZONE_DMA
+ */
+ zones = (NODE_DATA(node)->node_zonelists+ZONE_HIGHMEM)->zones;
+ for (i = 0; (z = zones[i]) && reclaimed < pages_to_reclaim; i++) {
+ if (!z->present_pages)
+ continue;
+ reclaimed += reclaim_clean_pages(z, pages_to_reclaim,
+ flags);
+ }
+
+ return reclaimed * PAGE_SIZE;
+}
+
+#ifdef CONFIG_COMPAT
+
+asmlinkage long compat_sys_reclaim_page_cache_node(compat_uint_t node,
+ compat_ulong_t bytes,
+ compat_uint_t flags)
+{
+ return sys_reclaim_page_cache_node(node, bytes, flags);
+}
+
+#endif
_