Messages in this thread Patch in this message | | | From | Ross Zwisler <> | Subject | [PATCH 2/2] libnvdimm: don't flush power-fail protected CPU caches | Date | Tue, 5 Jun 2018 14:58:41 -0600 |
| |
This commit:
5fdf8e5ba566 ("libnvdimm: re-enable deep flush for pmem devices via fsync()")
intended to make sure that deep flush was always available even on platforms which support a power-fail protected CPU cache. An unintended side effect of this change was that we also lost the ability to skip flushing CPU caches on those power-fail protected CPU cache.
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Fixes: 5fdf8e5ba566 ("libnvdimm: re-enable deep flush for pmem devices via fsync()") --- drivers/dax/super.c | 20 +++++++++++++++++++- drivers/nvdimm/pmem.c | 2 ++ include/linux/dax.h | 9 +++++++++ 3 files changed, 30 insertions(+), 1 deletion(-)
diff --git a/drivers/dax/super.c b/drivers/dax/super.c index c2c46f96b18c..457e0bb6c936 100644 --- a/drivers/dax/super.c +++ b/drivers/dax/super.c @@ -152,6 +152,8 @@ enum dax_device_flags { DAXDEV_ALIVE, /* gate whether dax_flush() calls the low level flush routine */ DAXDEV_WRITE_CACHE, + /* only flush the CPU caches if they are not power fail protected */ + DAXDEV_FLUSH_ON_SYNC, }; /** @@ -283,7 +285,8 @@ EXPORT_SYMBOL_GPL(dax_copy_from_iter); void arch_wb_cache_pmem(void *addr, size_t size); void dax_flush(struct dax_device *dax_dev, void *addr, size_t size) { - if (unlikely(!dax_write_cache_enabled(dax_dev))) + if (unlikely(!dax_write_cache_enabled(dax_dev)) || + !dax_flush_on_sync_enabled(dax_dev)) return; arch_wb_cache_pmem(addr, size); @@ -310,6 +313,21 @@ bool dax_write_cache_enabled(struct dax_device *dax_dev) } EXPORT_SYMBOL_GPL(dax_write_cache_enabled); +void dax_flush_on_sync(struct dax_device *dax_dev, bool flush) +{ + if (flush) + set_bit(DAXDEV_FLUSH_ON_SYNC, &dax_dev->flags); + else + clear_bit(DAXDEV_FLUSH_ON_SYNC, &dax_dev->flags); +} +EXPORT_SYMBOL_GPL(dax_flush_on_sync); + +bool dax_flush_on_sync_enabled(struct dax_device *dax_dev) +{ + return test_bit(DAXDEV_FLUSH_ON_SYNC, &dax_dev->flags); +} +EXPORT_SYMBOL_GPL(dax_flush_on_sync_enabled); + bool dax_alive(struct dax_device *dax_dev) { lockdep_assert_held(&dax_srcu); diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index 9d714926ecf5..faeb2deae7f0 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -414,6 +414,8 @@ static int pmem_attach_disk(struct device *dev, return -ENOMEM; } dax_write_cache(dax_dev, wbc); + dax_flush_on_sync(dax_dev, + !test_bit(ND_REGION_PERSIST_CACHE, &nd_region->flags)); pmem->dax_dev = dax_dev; gendev = disk_to_dev(disk); diff --git a/include/linux/dax.h b/include/linux/dax.h index f9eb22ad341e..1e6086405a1a 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -32,6 +32,8 @@ void put_dax(struct dax_device *dax_dev); void kill_dax(struct dax_device *dax_dev); void dax_write_cache(struct dax_device *dax_dev, bool wc); bool dax_write_cache_enabled(struct dax_device *dax_dev); +void dax_flush_on_sync(struct dax_device *dax_dev, bool flush); +bool dax_flush_on_sync_enabled(struct dax_device *dax_dev); #else static inline struct dax_device *dax_get_by_host(const char *host) { @@ -59,6 +61,13 @@ static inline bool dax_write_cache_enabled(struct dax_device *dax_dev) { return false; } +static inline void dax_flush_on_sync(struct dax_device *dax_dev, bool flush) +{ +} +static inline bool dax_flush_on_sync_enabled(struct dax_device *dax_dev) +{ + return false; +} #endif struct writeback_control; -- 2.14.4
| |