[PATCH 2/4] Add pgcollapse controls to task_struct

From: Alex Thorlton
Date: Thu Oct 23 2014 - 14:46:29 EST


This patch just adds the necessary bits to the task_struct so that the scans can
eventually be controlled on a per-mm basis. As I mentioned previously, we might
want to add some more counters here.

Signed-off-by: Alex Thorlton <athorlton@xxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Bob Liu <lliubbo@xxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Vladimir Davydov <vdavydov@xxxxxxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx

---
include/linux/sched.h | 12 ++++++++++++
kernel/fork.c | 6 ++++++
2 files changed, 18 insertions(+)

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 5e344bb..50f67d5 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1661,6 +1661,18 @@ struct task_struct {
unsigned int sequential_io;
unsigned int sequential_io_avg;
#endif
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+ struct callback_head pgcollapse_work;
+ /* default scan 8*512 pte (or vmas) every 30 second */
+ unsigned int pgcollapse_pages_to_scan;
+ unsigned int pgcollapse_pages_collapsed;
+ unsigned int pgcollapse_full_scans;
+ unsigned int pgcollapse_scan_sleep_millisecs;
+ /* during fragmentation poll the hugepage allocator once every minute */
+ unsigned int pgcollapse_alloc_sleep_millisecs;
+ unsigned long pgcollapse_last_scan;
+ unsigned long pgcollapse_scan_address;
+#endif
};

/* Future-safe accessor for struct task_struct's cpus_allowed. */
diff --git a/kernel/fork.c b/kernel/fork.c
index 9b7d746..8c55309 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1355,6 +1355,12 @@ static struct task_struct *copy_process(unsigned long clone_flags,
p->sequential_io = 0;
p->sequential_io_avg = 0;
#endif
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+ /* need to pull these values from sysctl or something */
+ p->pgcollapse_pages_to_scan = HPAGE_PMD_NR * 8;
+ p->pgcollapse_scan_sleep_millisecs = 10000;
+ p->pgcollapse_alloc_sleep_millisecs = 60000;
+#endif

/* Perform scheduler related setup. Assign this task to a CPU. */
retval = sched_fork(clone_flags, p);
--
1.7.12.4

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