The patch titled
mm: scalable bdi statistics counters.
has been added to the -mm tree. Its filename is
mm-scalable-bdi-statistics-counters.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: mm: scalable bdi statistics counters.
From: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Provide scalable per backing_dev_info statistics counters.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/backing-dev.h | 85 ++++++++++++++++++++++++++++++++--
mm/backing-dev.c | 27 ++++++++++
2 files changed, 109 insertions(+), 3 deletions(-)
diff -puN include/linux/backing-dev.h~mm-scalable-bdi-statistics-counters include/linux/backing-dev.h
--- a/include/linux/backing-dev.h~mm-scalable-bdi-statistics-counters
+++ a/include/linux/backing-dev.h
@@ -8,6 +8,8 @@
#ifndef _LINUX_BACKING_DEV_H
#define _LINUX_BACKING_DEV_H
+#include <linux/percpu_counter.h>
+#include <linux/log2.h>
#include <asm/atomic.h>
struct page;
@@ -24,6 +26,12 @@ enum bdi_state {
typedef int (congested_fn)(void *, int);
+enum bdi_stat_item {
+ NR_BDI_STAT_ITEMS
+};
+
+#define BDI_STAT_BATCH (8*(1+ilog2(nr_cpu_ids)))
+
struct backing_dev_info {
unsigned long ra_pages; /* max readahead in PAGE_CACHE_SIZE units */
unsigned long state; /* Always use atomic bitops on this */
@@ -32,15 +40,86 @@ struct backing_dev_info {
void *congested_data; /* Pointer to aux data for congested func */
void (*unplug_io_fn)(struct backing_dev_info *, struct page *);
void *unplug_io_data;
+
+ struct percpu_counter bdi_stat[NR_BDI_STAT_ITEMS];
};
-static inline int bdi_init(struct backing_dev_info *bdi)
+int bdi_init(struct backing_dev_info *bdi);
+void bdi_destroy(struct backing_dev_info *bdi);
+
+static inline void __mod_bdi_stat(struct backing_dev_info *bdi,
+ enum bdi_stat_item item, s32 amount)
{
- return 0;
+ __percpu_counter_add(&bdi->bdi_stat[item], amount, BDI_STAT_BATCH);
}
-static inline void bdi_destroy(struct backing_dev_info *bdi)
+static inline void __inc_bdi_stat(struct backing_dev_info *bdi,
+ enum bdi_stat_item item)
{
+ __mod_bdi_stat(bdi, item, 1);
+}
+
+static inline void inc_bdi_stat(struct backing_dev_info *bdi,
+ enum bdi_stat_item item)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ __inc_bdi_stat(bdi, item);
+ local_irq_restore(flags);
+}
+
+static inline void __dec_bdi_stat(struct backing_dev_info *bdi,
+ enum bdi_stat_item item)
+{
+ __mod_bdi_stat(bdi, item, -1);
+}
+
+static inline void dec_bdi_stat(struct backing_dev_info *bdi,
+ enum bdi_stat_item item)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ __dec_bdi_stat(bdi, item);
+ local_irq_restore(flags);
+}
+
+static inline s64 bdi_stat(struct backing_dev_info *bdi,
+ enum bdi_stat_item item)
+{
+ return percpu_counter_read_positive(&bdi->bdi_stat[item]);
+}
+
+static inline s64 __bdi_stat_sum(struct backing_dev_info *bdi,
+ enum bdi_stat_item item)
+{
+ return percpu_counter_sum_positive(&bdi->bdi_stat[item]);
+}
+
+static inline s64 bdi_stat_sum(struct backing_dev_info *bdi,
+ enum bdi_stat_item item)
+{
+ s64 sum;
+ unsigned long flags;
+
+ local_irq_save(flags);
+ sum = __bdi_stat_sum(bdi, item);
+ local_irq_restore(flags);
+
+ return sum;
+}
+
+/*
+ * maximal error of a stat counter.
+ */
+static inline unsigned long bdi_stat_error(struct backing_dev_info *bdi)
+{
+#ifdef CONFIG_SMP
+ return nr_cpu_ids * BDI_STAT_BATCH;
+#else
+ return 1;
+#endif
}
/*
diff -puN mm/backing-dev.c~mm-scalable-bdi-statistics-counters mm/backing-dev.c
--- a/mm/backing-dev.c~mm-scalable-bdi-statistics-counters
+++ a/mm/backing-dev.c
@@ -5,6 +5,33 @@
#include <linux/sched.h>
#include <linux/module.h>
+int bdi_init(struct backing_dev_info *bdi)
+{
+ int i, j;
+ int err;
+
+ for (i = 0; i < NR_BDI_STAT_ITEMS; i++) {
+ err = percpu_counter_init_irq(&bdi->bdi_stat[i], 0);
+ if (err) {
+ for (j = 0; j < i; j++)
+ perpcu_counter_destroy(&bdi->bdi_stat[i]);
+ break;
+ }
+ }
+
+ return err;
+}
+EXPORT_SYMBOL(bdi_init);
+
+void bdi_destroy(struct backing_dev_info *bdi)
+{
+ int i;
+
+ for (i = 0; i < NR_BDI_STAT_ITEMS; i++)
+ percpu_counter_destroy(&bdi->bdi_stat[i]);
+}
+EXPORT_SYMBOL(bdi_destroy);
+
static wait_queue_head_t congestion_wqh[2] = {
__WAIT_QUEUE_HEAD_INITIALIZER(congestion_wqh[0]),
__WAIT_QUEUE_HEAD_INITIALIZER(congestion_wqh[1])
_
Patches currently in -mm which might be from a.p.zijlstra@xxxxxxxxx are
radix-tree-use-indirect-bit.patch
nfs-remove-congestion_end.patch
lib-percpu_counter_add.patch
lib-percpu_counter-variable-batch.patch
lib-make-percpu_counter_add-take-s64.patch
lib-percpu_counter_set.patch
lib-percpu_counter_sum_positive.patch
lib-percpu_count_sum.patch
lib-percpu_counter_init-error-handling.patch
lib-percpu_counter_init_irq.patch
mm-bdi-init-hooks.patch
mtd-bdi-init-hooks.patch
mtd-clean-up-the-backing_dev_info-usage.patch
mtd-give-mtdconcat-devices-their-own-backing_dev_info.patch
mm-scalable-bdi-statistics-counters.patch
mm-count-reclaimable-pages-per-bdi.patch
mm-count-writeback-pages-per-bdi.patch
mm-expose-bdi-statistics-in-sysfs.patch
lib-floating-proportions.patch
lib-floating-proportions-_single.patch
mm-per-device-dirty-threshold.patch
mm-dirty-balancing-for-tasks.patch
debug-sysfs-files-for-the-current-ratio-size-total.patch
intel-iommu-dmar-detection-and-parsing-logic.patch
intel-iommu-pci-generic-helper-function.patch
intel-iommu-clflush_cache_range-now-takes-size-param.patch
intel-iommu-iova-allocation-and-management-routines.patch
intel-iommu-intel-iommu-driver.patch
intel-iommu-avoid-memory-allocation-failures-in-dma-map-api-calls.patch
intel-iommu-intel-iommu-cmdline-option-forcedac.patch
intel-iommu-dmar-fault-handling-support.patch
intel-iommu-iommu-gfx-workaround.patch
intel-iommu-iommu-floppy-workaround.patch
containers-bdi-init-hooks.patch
workqueue-debug-flushing-deadlocks-with-lockdep.patch
workqueue-debug-work-related-deadlocks-with-lockdep.patch
-
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
