[PATCH -mmotm 2/4] page_cgroup: introduce file cache flags

From: Andrea Righi
Date: Thu Mar 04 2010 - 05:40:45 EST


Introduce page_cgroup flags to keep track of file cache pages.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Signed-off-by: Andrea Righi <arighi@xxxxxxxxxxx>
---
include/linux/page_cgroup.h | 49 +++++++++++++++++++++++++++++++++++++++++++
1 files changed, 49 insertions(+), 0 deletions(-)

diff --git a/include/linux/page_cgroup.h b/include/linux/page_cgroup.h
index 30b0813..1b79ded 100644
--- a/include/linux/page_cgroup.h
+++ b/include/linux/page_cgroup.h
@@ -39,6 +39,12 @@ enum {
PCG_CACHE, /* charged as cache */
PCG_USED, /* this object is in use. */
PCG_ACCT_LRU, /* page has been accounted for */
+ PCG_MIGRATE_LOCK, /* used for mutual execution of account migration */
+ PCG_ACCT_FILE_MAPPED, /* page is accounted as file rss*/
+ PCG_ACCT_DIRTY, /* page is dirty */
+ PCG_ACCT_WRITEBACK, /* page is being written back to disk */
+ PCG_ACCT_WRITEBACK_TEMP, /* page is used as temporary buffer for FUSE */
+ PCG_ACCT_UNSTABLE_NFS, /* NFS page not yet committed to the server */
};

#define TESTPCGFLAG(uname, lname) \
@@ -73,6 +79,27 @@ CLEARPCGFLAG(AcctLRU, ACCT_LRU)
TESTPCGFLAG(AcctLRU, ACCT_LRU)
TESTCLEARPCGFLAG(AcctLRU, ACCT_LRU)

+/* File cache and dirty memory flags */
+TESTPCGFLAG(FileMapped, ACCT_FILE_MAPPED)
+SETPCGFLAG(FileMapped, ACCT_FILE_MAPPED)
+CLEARPCGFLAG(FileMapped, ACCT_FILE_MAPPED)
+
+TESTPCGFLAG(Dirty, ACCT_DIRTY)
+SETPCGFLAG(Dirty, ACCT_DIRTY)
+CLEARPCGFLAG(Dirty, ACCT_DIRTY)
+
+TESTPCGFLAG(Writeback, ACCT_WRITEBACK)
+SETPCGFLAG(Writeback, ACCT_WRITEBACK)
+CLEARPCGFLAG(Writeback, ACCT_WRITEBACK)
+
+TESTPCGFLAG(WritebackTemp, ACCT_WRITEBACK_TEMP)
+SETPCGFLAG(WritebackTemp, ACCT_WRITEBACK_TEMP)
+CLEARPCGFLAG(WritebackTemp, ACCT_WRITEBACK_TEMP)
+
+TESTPCGFLAG(UnstableNFS, ACCT_UNSTABLE_NFS)
+SETPCGFLAG(UnstableNFS, ACCT_UNSTABLE_NFS)
+CLEARPCGFLAG(UnstableNFS, ACCT_UNSTABLE_NFS)
+
static inline int page_cgroup_nid(struct page_cgroup *pc)
{
return page_to_nid(pc->page);
@@ -83,6 +110,9 @@ static inline enum zone_type page_cgroup_zid(struct page_cgroup *pc)
return page_zonenum(pc->page);
}

+/*
+ * lock_page_cgroup() should not be held under mapping->tree_lock
+ */
static inline void lock_page_cgroup(struct page_cgroup *pc)
{
bit_spin_lock(PCG_LOCK, &pc->flags);
@@ -93,6 +123,25 @@ static inline void unlock_page_cgroup(struct page_cgroup *pc)
bit_spin_unlock(PCG_LOCK, &pc->flags);
}

+/*
+ * Lock order is
+ * lock_page_cgroup()
+ * lock_page_cgroup_migrate()
+ *
+ * This lock is not be lock for charge/uncharge but for account moving.
+ * i.e. overwrite pc->mem_cgroup. The lock owner should guarantee by itself
+ * the page is uncharged while we hold this.
+ */
+static inline void lock_page_cgroup_migrate(struct page_cgroup *pc)
+{
+ bit_spin_lock(PCG_MIGRATE_LOCK, &pc->flags);
+}
+
+static inline void unlock_page_cgroup_migrate(struct page_cgroup *pc)
+{
+ bit_spin_unlock(PCG_MIGRATE_LOCK, &pc->flags);
+}
+
#else /* CONFIG_CGROUP_MEM_RES_CTLR */
struct page_cgroup;

--
1.6.3.3

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