[PATCH 06/10] mm: page_alloc: Distinguish between being unable to sleep, unwilling to unwilling and avoiding waking kswapd

From: Mel Gorman
Date: Wed Aug 12 2015 - 06:46:59 EST

__GFP_WAIT has been used to identify atomic context in callers that hold
spinlocks or are in interrupts. They are expected to be high priority and
have access one of two watermarks lower than "min". __GFP_HIGH users get
access to the first lower watermark and can be called the "high priority
reserve". Atomic users and interrupts access yet another lower watermark
that can be called the "atomic reserve".

Over time, callers had a requirement to not block when fallback options
were available. Some have abused __GFP_WAIT leading to a situation where
an optimisitic allocation with a fallback option can access atomic reserves.

This patch uses __GFP_ATOMIC to identify callers that are truely atomic,
cannot sleep and have no alternative. High priority users continue to use
__GFP_HIGH. __GFP_DIRECT_RECLAIM identifies callers that can sleep and are
willing to enter direct reclaim. __GFP_KSWAPD_RECLAIM to identify callers
that want to wake kswapd for background reclaim. __GFP_WAIT is redefined
as a caller that is willing to enter direct reclaim and wake kswapd for
background reclaim.

This patch then converts a number of sites

o __GFP_ATOMIC is used by callers that are high priority and have memory
pools for those requests. GFP_ATOMIC uses this flag. Callers with
interrupts disabled still automatically use the atomic reserves.

o Callers that have a limited mempool to guarantee forward progress use
__GFP_DIRECT_RECLAIM. bio allocations fall into this category where
kswapd will still be woken but atomic reserves are not used as there
is a one-entry mempool to guarantee progress.

o Callers that are checking if they are non-blocking should use the
helper gfpflags_allows_blocking() where possible. This is because
checking for __GFP_WAIT as was done historically now can trigger false
positives. Some exceptions like dm-crypt.c exist where the code intent
is clearer if __GFP_DIRECT_RECLAIM is used instead of the helper due to
flag manipulations.

The key hazard to watch out for is callers that removed __GFP_WAIT and
was depending on access to atomic reserves for inconspicuous reasons.
In some cases it may be appropriate for them to use __GFP_HIGH.

Signed-off-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
---
Documentation/vm/balance | 14 ++++----
arch/arm/mm/dma-mapping.c | 4 +--
arch/arm64/mm/dma-mapping.c | 4 +--
arch/x86/kernel/pci-dma.c | 2 +-
block/bio.c | 26 +++++++--------
block/blk-core.c | 16 ++++-----
block/blk-ioc.c | 2 +-
block/blk-mq-tag.c | 2 +-
block/blk-mq.c | 8 ++---
block/cfq-iosched.c | 4 +--
drivers/block/osdblk.c | 2 +-
drivers/connector/connector.c | 3 +-
drivers/firewire/core-cdev.c | 2 +-
drivers/gpu/drm/i915/i915_gem.c | 2 +-
drivers/infiniband/core/sa_query.c | 2 +-
drivers/iommu/amd_iommu.c | 2 +-
drivers/iommu/intel-iommu.c | 2 +-
drivers/md/dm-crypt.c | 6 ++--
drivers/mtd/mtdcore.c | 3 +-
drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c | 2 +-
drivers/staging/android/ion/ion_system_heap.c | 2 +-
drivers/usb/host/u132-hcd.c | 2 +-
fs/btrfs/disk-io.c | 2 +-
fs/btrfs/extent_io.c | 8 ++---
fs/btrfs/volumes.c | 4 +--
fs/ext3/super.c | 2 +-
fs/ext4/super.c | 2 +-
fs/fscache/cookie.c | 2 +-
fs/fscache/page.c | 6 ++--
fs/jbd/transaction.c | 4 +--
fs/jbd2/transaction.c | 4 +--
fs/nfs/file.c | 6 ++--
fs/xfs/xfs_qm.c | 2 +-
include/linux/gfp.h | 44 ++++++++++++++++++-------
include/linux/skbuff.h | 6 ++--
include/net/sock.h | 2 +-
include/trace/events/gfpflags.h | 5 +--
kernel/audit.c | 6 ++--
kernel/locking/lockdep.c | 2 +-
kernel/smp.c | 2 +-
lib/idr.c | 4 +--
lib/radix-tree.c | 10 +++---
mm/backing-dev.c | 2 +-
mm/dmapool.c | 2 +-
mm/memcontrol.c | 8 ++---
mm/mempool.c | 10 +++---
mm/page_alloc.c | 29 +++++++++-------
mm/slab.c | 18 +++++-----
mm/slub.c | 6 ++--
mm/vmalloc.c | 2 +-
mm/vmscan.c | 2 +-
net/core/skbuff.c | 8 ++---
net/core/sock.c | 6 ++--
net/sctp/associola.c | 2 +-
54 files changed, 181 insertions(+), 149 deletions(-)

diff --git a/Documentation/vm/balance b/Documentation/vm/balance
index c46e68cf9344..6f1f6fae30f5 100644
--- a/Documentation/vm/balance
+++ b/Documentation/vm/balance
@@ -1,12 +1,14 @@
Started Jan 2000 by Kanoj Sarcar <kanoj@xxxxxxx>

-Memory balancing is needed for non __GFP_WAIT as well as for non
-__GFP_IO allocations.
+Memory balancing is needed for !__GFP_ATOMIC and !__GFP_KSWAPD_RECLAIM as
+well as for non __GFP_IO allocations.

-There are two reasons to be requesting non __GFP_WAIT allocations:
-the caller can not sleep (typically intr context), or does not want
-to incur cost overheads of page stealing and possible swap io for
-whatever reasons.
+The first reason why a caller may avoid reclaim is that the caller can not
+sleep due to holding a spinlock or is in interrupt context. The second may
+be that the caller is willing to fail the allocation without incurring the
+overhead of page stealing. This may happen for opportunistic high-order
+allocation requests that have order-0 fallback options. In such cases,
+the caller may also wish to avoid waking kswapd.

__GFP_IO allocation requests are made to prevent file system deadlocks.

diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index cba12f34ff77..100d3fbaebae 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -650,7 +650,7 @@ static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,

if (is_coherent || nommu())
addr = __alloc_simple_buffer(dev, size, gfp, &page);
- else if (!(gfp & __GFP_WAIT))
+ else if (gfp & __GFP_ATOMIC)
addr = __alloc_from_pool(size, &page);
else if (!dev_get_cma_area(dev))
addr = __alloc_remap_buffer(dev, size, gfp, prot, &page, caller, want_vaddr);
@@ -1369,7 +1369,7 @@ static void *arm_iommu_alloc_attrs(struct device *dev, size_t size,
*handle = DMA_ERROR_CODE;
size = PAGE_ALIGN(size);

- if (!(gfp & __GFP_WAIT))
+ if (gfp & __GFP_ATOMIC)
return __iommu_alloc_atomic(dev, size, handle);

/*
diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index d16a1cead23f..713d963fb96b 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -100,7 +100,7 @@ static void *__dma_alloc_coherent(struct device *dev, size_t size,
if (IS_ENABLED(CONFIG_ZONE_DMA) &&
dev->coherent_dma_mask <= DMA_BIT_MASK(32))
flags |= GFP_DMA;
- if (IS_ENABLED(CONFIG_DMA_CMA) && (flags & __GFP_WAIT)) {
+ if (IS_ENABLED(CONFIG_DMA_CMA) && (flags & __GFP_DIRECT_RECLAIM)) {
struct page *page;
void *addr;

@@ -147,7 +147,7 @@ static void *__dma_alloc(struct device *dev, size_t size,

size = PAGE_ALIGN(size);

- if (!coherent && !(flags & __GFP_WAIT)) {
+ if (!coherent && (flags & __GFP_ATOMIC)) {
struct page *page = NULL;
void *addr = __alloc_from_pool(size, &page, flags);

diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index 353972c1946c..9a13ebb0f621 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -101,7 +101,7 @@ void *dma_generic_alloc_coherent(struct device *dev, size_t size,
again:
page = NULL;
/* CMA can be used only in the context which permits sleeping */
- if (flag & __GFP_WAIT) {
+ if (flag & __GFP_DIRECT_RECLAIM) {
page = dma_alloc_from_contiguous(dev, count, get_order(size));
if (page && page_to_phys(page) + size > dma_mask) {
dma_release_from_contiguous(dev, page, count);
diff --git a/block/bio.c b/block/bio.c
index d6e5ba3399f0..fbc558b50e67 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -211,7 +211,7 @@ struct bio_vec *bvec_alloc(gfp_t gfp_mask, int nr, unsigned long *idx,
bvl = mempool_alloc(pool, gfp_mask);
} else {
struct biovec_slab *bvs = bvec_slabs + *idx;
- gfp_t __gfp_mask = gfp_mask & ~(__GFP_WAIT | __GFP_IO);
+ gfp_t __gfp_mask = gfp_mask & ~(__GFP_DIRECT_RECLAIM | __GFP_IO);

/*
* Make this allocation restricted and don't dump info on
@@ -221,11 +221,11 @@ struct bio_vec *bvec_alloc(gfp_t gfp_mask, int nr, unsigned long *idx,
__gfp_mask |= __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN;

/*
- * Try a slab allocation. If this fails and __GFP_WAIT
+ * Try a slab allocation. If this fails and __GFP_DIRECT_RECLAIM
* is set, retry with the 1-entry mempool
*/
bvl = kmem_cache_alloc(bvs->slab, __gfp_mask);
- if (unlikely(!bvl && (gfp_mask & __GFP_WAIT))) {
+ if (unlikely(!bvl && (gfp_mask & __GFP_DIRECT_RECLAIM))) {
*idx = BIOVEC_MAX_IDX;
goto fallback;
}
@@ -393,12 +393,12 @@ static void punt_bios_to_rescuer(struct bio_set *bs)
* If @bs is NULL, uses kmalloc() to allocate the bio; else the allocation is
* backed by the @bs's mempool.
*
- * When @bs is not NULL, if %__GFP_WAIT is set then bio_alloc will always be
- * able to allocate a bio. This is due to the mempool guarantees. To make this
- * work, callers must never allocate more than 1 bio at a time from this pool.
- * Callers that need to allocate more than 1 bio must always submit the
- * previously allocated bio for IO before attempting to allocate a new one.
- * Failure to do so can cause deadlocks under memory pressure.
+ * When @bs is not NULL, if %__GFP_DIRECT_RECLAIM is set then bio_alloc will
+ * always be able to allocate a bio. This is due to the mempool guarantees.
+ * To make this work, callers must never allocate more than 1 bio at a time
+ * from this pool. Callers that need to allocate more than 1 bio must always
+ * submit the previously allocated bio for IO before attempting to allocate
+ * a new one. Failure to do so can cause deadlocks under memory pressure.
*
* Note that when running under generic_make_request() (i.e. any block
* driver), bios are not submitted until after you return - see the code in
@@ -457,13 +457,13 @@ struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs)
* We solve this, and guarantee forward progress, with a rescuer
* workqueue per bio_set. If we go to allocate and there are
* bios on current->bio_list, we first try the allocation
- * without __GFP_WAIT; if that fails, we punt those bios we
- * would be blocking to the rescuer workqueue before we retry
- * with the original gfp_flags.
+ * without __GFP_DIRECT_RECLAIM; if that fails, we punt those
+ * bios we would be blocking to the rescuer workqueue before
+ * we retry with the original gfp_flags.
*/

if (current->bio_list && !bio_list_empty(current->bio_list))
- gfp_mask &= ~__GFP_WAIT;
+ gfp_mask &= ~__GFP_DIRECT_RECLAIM;

p = mempool_alloc(bs->bio_pool, gfp_mask);
if (!p && gfp_mask != saved_gfp) {
diff --git a/block/blk-core.c b/block/blk-core.c
index 627ed0c593fb..c53c2513d472 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1156,8 +1156,8 @@ static struct request *__get_request(struct request_list *rl, int rw_flags,
* @bio: bio to allocate request for (can be %NULL)
* @gfp_mask: allocation mask
*
- * Get a free request from @q. If %__GFP_WAIT is set in @gfp_mask, this
- * function keeps retrying under memory pressure and fails iff @q is dead.
+ * Get a free request from @q. If %__GFP_DIRECT_RECLAIM is set in @gfp_mask,
+ * this function keeps retrying under memory pressure and fails iff @q is dead.
*
* Must be called with @q->queue_lock held and,
* Returns ERR_PTR on failure, with @q->queue_lock held.
@@ -1177,7 +1177,7 @@ static struct request *get_request(struct request_queue *q, int rw_flags,
if (!IS_ERR(rq))
return rq;

- if (!(gfp_mask & __GFP_WAIT) || unlikely(blk_queue_dying(q))) {
+ if (!gfpflags_allows_blocking(gfp_mask) || unlikely(blk_queue_dying(q))) {
blk_put_rl(rl);
return rq;
}
@@ -1255,11 +1255,11 @@ EXPORT_SYMBOL(blk_get_request);
* BUG.
*
* WARNING: When allocating/cloning a bio-chain, careful consideration should be
- * given to how you allocate bios. In particular, you cannot use __GFP_WAIT for
- * anything but the first bio in the chain. Otherwise you risk waiting for IO
- * completion of a bio that hasn't been submitted yet, thus resulting in a
- * deadlock. Alternatively bios should be allocated using bio_kmalloc() instead
- * of bio_alloc(), as that avoids the mempool deadlock.
+ * given to how you allocate bios. In particular, you cannot use
+ * __GFP_DIRECT_RECLAIM for anything but the first bio in the chain. Otherwise
+ * you risk waiting for IO completion of a bio that hasn't been submitted yet,
+ * thus resulting in a deadlock. Alternatively bios should be allocated using
+ * bio_kmalloc() instead of bio_alloc(), as that avoids the mempool deadlock.
* If possible a big IO should be split into smaller parts when allocation
* fails. Partial allocation should not be an error, or you risk a live-lock.
*/
diff --git a/block/blk-ioc.c b/block/blk-ioc.c
index 1a27f45ec776..0e7e7d9ffc04 100644
--- a/block/blk-ioc.c
+++ b/block/blk-ioc.c
@@ -289,7 +289,7 @@ struct io_context *get_task_io_context(struct task_struct *task,
{
struct io_context *ioc;

- might_sleep_if(gfp_flags & __GFP_WAIT);
+ might_sleep_if(gfpflags_allows_blocking(gfp_flags));

do {
task_lock(task);
diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c
index 9b6e28830b82..7e27f6164298 100644
--- a/block/blk-mq-tag.c
+++ b/block/blk-mq-tag.c
@@ -264,7 +264,7 @@ static int bt_get(struct blk_mq_alloc_data *data,
if (tag != -1)
return tag;

- if (!(data->gfp & __GFP_WAIT))
+ if (!gfpflags_allows_blocking(data->gfp))
return -1;

bs = bt_wait_ptr(bt, hctx);
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 7d842db59699..df8cba632ec2 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -85,7 +85,7 @@ static int blk_mq_queue_enter(struct request_queue *q, gfp_t gfp)
if (percpu_ref_tryget_live(&q->mq_usage_counter))
return 0;

- if (!(gfp & __GFP_WAIT))
+ if (!gfpflags_allows_blocking(gfp))
return -EBUSY;

ret = wait_event_interruptible(q->mq_freeze_wq,
@@ -261,11 +261,11 @@ struct request *blk_mq_alloc_request(struct request_queue *q, int rw, gfp_t gfp,

ctx = blk_mq_get_ctx(q);
hctx = q->mq_ops->map_queue(q, ctx->cpu);
- blk_mq_set_alloc_data(&alloc_data, q, gfp & ~__GFP_WAIT,
+ blk_mq_set_alloc_data(&alloc_data, q, gfp & ~__GFP_DIRECT_RECLAIM,
reserved, ctx, hctx);

rq = __blk_mq_alloc_request(&alloc_data, rw);
- if (!rq && (gfp & __GFP_WAIT)) {
+ if (!rq && (gfp & __GFP_DIRECT_RECLAIM)) {
__blk_mq_run_hw_queue(hctx);
blk_mq_put_ctx(ctx);

@@ -1221,7 +1221,7 @@ static struct request *blk_mq_map_request(struct request_queue *q,
ctx = blk_mq_get_ctx(q);
hctx = q->mq_ops->map_queue(q, ctx->cpu);
blk_mq_set_alloc_data(&alloc_data, q,
- __GFP_WAIT|GFP_ATOMIC, false, ctx, hctx);
+ __GFP_WAIT|__GFP_HIGH, false, ctx, hctx);
rq = __blk_mq_alloc_request(&alloc_data, rw);
ctx = alloc_data.ctx;
hctx = alloc_data.hctx;
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index c62bb2e650b8..4c7ca678856a 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -3674,7 +3674,7 @@ cfq_find_alloc_queue(struct cfq_data *cfqd, bool is_sync, struct cfq_io_cq *cic,
if (new_cfqq) {
cfqq = new_cfqq;
new_cfqq = NULL;
- } else if (gfp_mask & __GFP_WAIT) {
+ } else if (gfp_mask & __GFP_DIRECT_RECLAIM) {
rcu_read_unlock();
spin_unlock_irq(cfqd->queue->queue_lock);
new_cfqq = kmem_cache_alloc_node(cfq_pool,
@@ -4289,7 +4289,7 @@ cfq_set_request(struct request_queue *q, struct request *rq, struct bio *bio,
const bool is_sync = rq_is_sync(rq);
struct cfq_queue *cfqq;

- might_sleep_if(gfp_mask & __GFP_WAIT);
+ might_sleep_if(gfpflags_allows_blocking(gfp_mask));

spin_lock_irq(q->queue_lock);

diff --git a/drivers/block/osdblk.c b/drivers/block/osdblk.c
index e22942596207..1b709a4e3b5e 100644
--- a/drivers/block/osdblk.c
+++ b/drivers/block/osdblk.c
@@ -271,7 +271,7 @@ static struct bio *bio_chain_clone(struct bio *old_chain, gfp_t gfpmask)
goto err_out;

tmp->bi_bdev = NULL;
- gfpmask &= ~__GFP_WAIT;
+ gfpmask &= ~__GFP_DIRECT_RECLAIM;
tmp->bi_next = NULL;

if (!new_chain)
diff --git a/drivers/connector/connector.c b/drivers/connector/connector.c
index 30f522848c73..6255c8df6ae9 100644
--- a/drivers/connector/connector.c
+++ b/drivers/connector/connector.c
@@ -124,7 +124,8 @@ int cn_netlink_send_mult(struct cn_msg *msg, u16 len, u32 portid, u32 __group,
if (group)
return netlink_broadcast(dev->nls, skb, portid, group,
gfp_mask);
- return netlink_unicast(dev->nls, skb, portid, !(gfp_mask&__GFP_WAIT));
+ return netlink_unicast(dev->nls, skb, portid,
+ !gfpflags_allows_blocking(gfp_mask));
}
EXPORT_SYMBOL_GPL(cn_netlink_send_mult);

diff --git a/drivers/firewire/core-cdev.c b/drivers/firewire/core-cdev.c
index 2a3973a7c441..dc611c8cad10 100644
--- a/drivers/firewire/core-cdev.c
+++ b/drivers/firewire/core-cdev.c
@@ -486,7 +486,7 @@ static int ioctl_get_info(struct client *client, union ioctl_arg *arg)
static int add_client_resource(struct client *client,
struct client_resource *resource, gfp_t gfp_mask)
{
- bool preload = !!(gfp_mask & __GFP_WAIT);
+ bool preload = !!(gfp_mask & __GFP_DIRECT_RECLAIM);
unsigned long flags;
int ret;

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 52b446b27b4d..c2b45081c5ab 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2225,7 +2225,7 @@ i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj)
*/
mapping = file_inode(obj->base.filp)->i_mapping;
gfp = mapping_gfp_mask(mapping);
- gfp |= __GFP_NORETRY | __GFP_NOWARN | __GFP_NO_KSWAPD;
+ gfp |= __GFP_NORETRY | __GFP_NOWARN;
gfp &= ~(__GFP_IO | __GFP_WAIT);
sg = st->sgl;
st->nents = 0;
diff --git a/drivers/infiniband/core/sa_query.c b/drivers/infiniband/core/sa_query.c
index ca919f429666..76cf4cee3d64 100644
--- a/drivers/infiniband/core/sa_query.c
+++ b/drivers/infiniband/core/sa_query.c
@@ -619,7 +619,7 @@ static void init_mad(struct ib_sa_mad *mad, struct ib_mad_agent *agent)

static int send_mad(struct ib_sa_query *query, int timeout_ms, gfp_t gfp_mask)
{
- bool preload = !!(gfp_mask & __GFP_WAIT);
+ bool preload = !!(gfp_mask & __GFP_DIRECT_RECLAIM);
unsigned long flags;
int ret, id;

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 658ee39e6569..f4adbe89cd20 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -2755,7 +2755,7 @@ static void *alloc_coherent(struct device *dev, size_t size,

page = alloc_pages(flag | __GFP_NOWARN, get_order(size));
if (!page) {
- if (!(flag & __GFP_WAIT))
+ if (!gfpflags_allows_blocking(flag))
return NULL;

page = dma_alloc_from_contiguous(dev, size >> PAGE_SHIFT,
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 0649b94f5958..0f614d66eb03 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -3566,7 +3566,7 @@ static void *intel_alloc_coherent(struct device *dev, size_t size,
flags |= GFP_DMA32;
}

- if (flags & __GFP_WAIT) {
+ if (gfpflags_allows_blocking(flags)) {
unsigned int count = size >> PAGE_SHIFT;

page = dma_alloc_from_contiguous(dev, count, order);
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 0f48fed44a17..6dda08385309 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -993,7 +993,7 @@ static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size)
struct bio_vec *bvec;

retry:
- if (unlikely(gfp_mask & __GFP_WAIT))
+ if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM))
mutex_lock(&cc->bio_alloc_lock);

clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs);
@@ -1009,7 +1009,7 @@ static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size)
if (!page) {
crypt_free_buffer_pages(cc, clone);
bio_put(clone);
- gfp_mask |= __GFP_WAIT;
+ gfp_mask |= __GFP_DIRECT_RECLAIM;
goto retry;
}

@@ -1026,7 +1026,7 @@ static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size)
}

return_clone:
- if (unlikely(gfp_mask & __GFP_WAIT))
+ if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM))
mutex_unlock(&cc->bio_alloc_lock);

return clone;
diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 8bbbb751bf45..2dfb291a47c6 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -1188,8 +1188,7 @@ EXPORT_SYMBOL_GPL(mtd_writev);
*/
void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size)
{
- gfp_t flags = __GFP_NOWARN | __GFP_WAIT |
- __GFP_NORETRY | __GFP_NO_KSWAPD;
+ gfp_t flags = __GFP_NOWARN | __GFP_DIRECT_RECLAIM | __GFP_NORETRY;
size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE);
void *kbuf;

diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
index a90d7364334f..8458329a877e 100644
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
@@ -689,7 +689,7 @@ static void *bnx2x_frag_alloc(const struct bnx2x_fastpath *fp, gfp_t gfp_mask)
{
if (fp->rx_frag_size) {
/* GFP_KERNEL allocations are used only during initialization */
- if (unlikely(gfp_mask & __GFP_WAIT))
+ if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM))
return (void *)__get_free_page(gfp_mask);

return netdev_alloc_frag(fp->rx_frag_size);
diff --git a/drivers/staging/android/ion/ion_system_heap.c b/drivers/staging/android/ion/ion_system_heap.c
index da2a63c0a9ba..2615e0ae4f0a 100644
--- a/drivers/staging/android/ion/ion_system_heap.c
+++ b/drivers/staging/android/ion/ion_system_heap.c
@@ -27,7 +27,7 @@
#include "ion_priv.h"

static gfp_t high_order_gfp_flags = (GFP_HIGHUSER | __GFP_ZERO | __GFP_NOWARN |
- __GFP_NORETRY) & ~__GFP_WAIT;
+ __GFP_NORETRY) & ~__GFP_DIRECT_RECLAIM;
static gfp_t low_order_gfp_flags = (GFP_HIGHUSER | __GFP_ZERO | __GFP_NOWARN);
static const unsigned int orders[] = {8, 4, 0};
static const int num_orders = ARRAY_SIZE(orders);
diff --git a/drivers/usb/host/u132-hcd.c b/drivers/usb/host/u132-hcd.c
index d51687780b61..06badad3ab75 100644
--- a/drivers/usb/host/u132-hcd.c
+++ b/drivers/usb/host/u132-hcd.c
@@ -2247,7 +2247,7 @@ static int u132_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
{
struct u132 *u132 = hcd_to_u132(hcd);
if (irqs_disabled()) {
- if (__GFP_WAIT & mem_flags) {
+ if (__GFP_DIRECT_RECLAIM & mem_flags) {
printk(KERN_ERR "invalid context for function that migh"
"t sleep\n");
return -EINVAL;
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index f556c3732c2c..3dd4792b8099 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2566,7 +2566,7 @@ int open_ctree(struct super_block *sb,
fs_info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL;
fs_info->avg_delayed_ref_runtime = NSEC_PER_SEC >> 6; /* div by 64 */
/* readahead state */
- INIT_RADIX_TREE(&fs_info->reada_tree, GFP_NOFS & ~__GFP_WAIT);
+ INIT_RADIX_TREE(&fs_info->reada_tree, GFP_NOFS & ~__GFP_DIRECT_RECLAIM);
spin_lock_init(&fs_info->reada_lock);

fs_info->thread_pool_size = min_t(unsigned long,
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 02d05817cbdf..35660da77921 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -594,7 +594,7 @@ int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
if (bits & (EXTENT_IOBITS | EXTENT_BOUNDARY))
clear = 1;
again:
- if (!prealloc && (mask & __GFP_WAIT)) {
+ if (!prealloc && (mask & __GFP_DIRECT_RECLAIM)) {
/*
* Don't care for allocation failure here because we might end
* up not needing the pre-allocated extent state at all, which
@@ -850,7 +850,7 @@ __set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,

bits |= EXTENT_FIRST_DELALLOC;
again:
- if (!prealloc && (mask & __GFP_WAIT)) {
+ if (!prealloc && (mask & __GFP_DIRECT_RECLAIM)) {
prealloc = alloc_extent_state(mask);
BUG_ON(!prealloc);
}
@@ -1076,7 +1076,7 @@ int convert_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
btrfs_debug_check_extent_io_range(tree, start, end);

again:
- if (!prealloc && (mask & __GFP_WAIT)) {
+ if (!prealloc && (mask & __GFP_DIRECT_RECLAIM)) {
/*
* Best effort, don't worry if extent state allocation fails
* here for the first iteration. We might have a cached state
@@ -4265,7 +4265,7 @@ int try_release_extent_mapping(struct extent_map_tree *map,
u64 start = page_offset(page);
u64 end = start + PAGE_CACHE_SIZE - 1;

- if ((mask & __GFP_WAIT) &&
+ if ((mask & __GFP_DIRECT_RECLAIM) &&
page->mapping->host->i_size > 16 * 1024 * 1024) {
u64 len;
while (start <= end) {
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index fbe7c104531c..b1968f36a39b 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -156,8 +156,8 @@ static struct btrfs_device *__alloc_device(void)
spin_lock_init(&dev->reada_lock);
atomic_set(&dev->reada_in_flight, 0);
atomic_set(&dev->dev_stats_ccnt, 0);
- INIT_RADIX_TREE(&dev->reada_zones, GFP_NOFS & ~__GFP_WAIT);
- INIT_RADIX_TREE(&dev->reada_extents, GFP_NOFS & ~__GFP_WAIT);
+ INIT_RADIX_TREE(&dev->reada_zones, GFP_NOFS & ~__GFP_DIRECT_RECLAIM);
+ INIT_RADIX_TREE(&dev->reada_extents, GFP_NOFS & ~__GFP_DIRECT_RECLAIM);

return dev;
}
diff --git a/fs/ext3/super.c b/fs/ext3/super.c
index 5ed0044fbb37..9004c786716f 100644
--- a/fs/ext3/super.c
+++ b/fs/ext3/super.c
@@ -750,7 +750,7 @@ static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
return 0;
if (journal)
return journal_try_to_free_buffers(journal, page,
- wait & ~__GFP_WAIT);
+ wait & ~__GFP_DIRECT_RECLAIM);
return try_to_free_buffers(page);
}

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 58987b5c514b..abe76d41ef1e 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1045,7 +1045,7 @@ static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
return 0;
if (journal)
return jbd2_journal_try_to_free_buffers(journal, page,
- wait & ~__GFP_WAIT);
+ wait & ~__GFP_DIRECT_RECLAIM);
return try_to_free_buffers(page);
}

diff --git a/fs/fscache/cookie.c b/fs/fscache/cookie.c
index d403c69bee08..4304072161aa 100644
--- a/fs/fscache/cookie.c
+++ b/fs/fscache/cookie.c
@@ -111,7 +111,7 @@ struct fscache_cookie *__fscache_acquire_cookie(

/* radix tree insertion won't use the preallocation pool unless it's
* told it may not wait */
- INIT_RADIX_TREE(&cookie->stores, GFP_NOFS & ~__GFP_WAIT);
+ INIT_RADIX_TREE(&cookie->stores, GFP_NOFS & ~__GFP_DIRECT_RECLAIM);

switch (cookie->def->type) {
case FSCACHE_COOKIE_TYPE_INDEX:
diff --git a/fs/fscache/page.c b/fs/fscache/page.c
index 483bbc613bf0..79483b3d8c6f 100644
--- a/fs/fscache/page.c
+++ b/fs/fscache/page.c
@@ -58,7 +58,7 @@ bool release_page_wait_timeout(struct fscache_cookie *cookie, struct page *page)

/*
* decide whether a page can be released, possibly by cancelling a store to it
- * - we're allowed to sleep if __GFP_WAIT is flagged
+ * - we're allowed to sleep if __GFP_DIRECT_RECLAIM is flagged
*/
bool __fscache_maybe_release_page(struct fscache_cookie *cookie,
struct page *page,
@@ -122,7 +122,7 @@ bool __fscache_maybe_release_page(struct fscache_cookie *cookie,
* allocator as the work threads writing to the cache may all end up
* sleeping on memory allocation, so we may need to impose a timeout
* too. */
- if (!(gfp & __GFP_WAIT) || !(gfp & __GFP_FS)) {
+ if (!(gfp & __GFP_DIRECT_RECLAIM) || !(gfp & __GFP_FS)) {
fscache_stat(&fscache_n_store_vmscan_busy);
return false;
}
@@ -132,7 +132,7 @@ bool __fscache_maybe_release_page(struct fscache_cookie *cookie,
_debug("fscache writeout timeout page: %p{%lx}",
page, page->index);

- gfp &= ~__GFP_WAIT;
+ gfp &= ~__GFP_DIRECT_RECLAIM;
goto try_again;
}
EXPORT_SYMBOL(__fscache_maybe_release_page);
diff --git a/fs/jbd/transaction.c b/fs/jbd/transaction.c
index 1695ba8334a2..f45b90ba7c5c 100644
--- a/fs/jbd/transaction.c
+++ b/fs/jbd/transaction.c
@@ -1690,8 +1690,8 @@ __journal_try_to_free_buffer(journal_t *journal, struct buffer_head *bh)
* @journal: journal for operation
* @page: to try and free
* @gfp_mask: we use the mask to detect how hard should we try to release
- * buffers. If __GFP_WAIT and __GFP_FS is set, we wait for commit code to
- * release the buffers.
+ * buffers. If __GFP_DIRECT_RECLAIM and __GFP_FS is set, we wait for commit
+ * code to release the buffers.
*
*
* For all the buffers on this page,
diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c
index f3d06174b051..06e18bcdb888 100644
--- a/fs/jbd2/transaction.c
+++ b/fs/jbd2/transaction.c
@@ -1893,8 +1893,8 @@ __journal_try_to_free_buffer(journal_t *journal, struct buffer_head *bh)
* @journal: journal for operation
* @page: to try and free
* @gfp_mask: we use the mask to detect how hard should we try to release
- * buffers. If __GFP_WAIT and __GFP_FS is set, we wait for commit code to
- * release the buffers.
+ * buffers. If __GFP_DIRECT_RECLAIM and __GFP_FS is set, we wait for commit
+ * code to release the buffers.
*
*
* For all the buffers on this page,
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index cc4fa1ed61fc..5664e1938da1 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -480,8 +480,8 @@ static int nfs_release_page(struct page *page, gfp_t gfp)
dfprintk(PAGECACHE, "NFS: release_page(%p)\n", page);

/* Always try to initiate a 'commit' if relevant, but only
- * wait for it if __GFP_WAIT is set. Even then, only wait 1
- * second and only if the 'bdi' is not congested.
+ * wait for it if __GFP_DIRECT_RECLAIM is set. Even then,
+ * only wait 1 second and only if the 'bdi' is not congested.
* Waiting indefinitely can cause deadlocks when the NFS
* server is on this machine, when a new TCP connection is
* needed and in other rare cases. There is no particular
@@ -491,7 +491,7 @@ static int nfs_release_page(struct page *page, gfp_t gfp)
if (mapping) {
struct nfs_server *nfss = NFS_SERVER(mapping->host);
nfs_commit_inode(mapping->host, 0);
- if ((gfp & __GFP_WAIT) &&
+ if ((gfp & __GFP_DIRECT_RECLAIM) &&
!bdi_write_congested(&nfss->backing_dev_info)) {
wait_on_page_bit_killable_timeout(page, PG_private,
HZ);
diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c
index eac9549efd52..587174fd4f2c 100644
--- a/fs/xfs/xfs_qm.c
+++ b/fs/xfs/xfs_qm.c
@@ -525,7 +525,7 @@ xfs_qm_shrink_scan(
unsigned long freed;
int error;

- if ((sc->gfp_mask & (__GFP_FS|__GFP_WAIT)) != (__GFP_FS|__GFP_WAIT))
+ if ((sc->gfp_mask & (__GFP_FS|__GFP_DIRECT_RECLAIM)) != (__GFP_FS|__GFP_DIRECT_RECLAIM))
return 0;

INIT_LIST_HEAD(&isol.buffers);
diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index 43246850a85f..dbd246a14e2f 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -29,12 +29,13 @@ struct vm_area_struct;
#define ___GFP_NOMEMALLOC 0x10000u
#define ___GFP_HARDWALL 0x20000u
#define ___GFP_THISNODE 0x40000u
-#define ___GFP_WAIT 0x80000u
+#define ___GFP_ATOMIC 0x80000u
#define ___GFP_NOACCOUNT 0x100000u
#define ___GFP_NOTRACK 0x200000u
-#define ___GFP_NO_KSWAPD 0x400000u
+#define ___GFP_DIRECT_RECLAIM 0x400000u
#define ___GFP_OTHER_NODE 0x800000u
#define ___GFP_WRITE 0x1000000u
+#define ___GFP_KSWAPD_RECLAIM 0x2000000u
/* If the above are modified, __GFP_BITS_SHIFT may need updating */

/*
@@ -68,7 +69,7 @@ struct vm_area_struct;
* __GFP_MOVABLE: Flag that this page will be movable by the page migration
* mechanism or reclaimed
*/
-#define __GFP_WAIT ((__force gfp_t)___GFP_WAIT) /* Can wait and reschedule? */
+#define __GFP_ATOMIC ((__force gfp_t)___GFP_ATOMIC) /* Caller cannot wait or reschedule */
#define __GFP_HIGH ((__force gfp_t)___GFP_HIGH) /* Should access emergency pools? */
#define __GFP_IO ((__force gfp_t)___GFP_IO) /* Can start physical IO? */
#define __GFP_FS ((__force gfp_t)___GFP_FS) /* Can call down to low-level FS? */
@@ -91,23 +92,37 @@ struct vm_area_struct;
#define __GFP_NOACCOUNT ((__force gfp_t)___GFP_NOACCOUNT) /* Don't account to kmemcg */
#define __GFP_NOTRACK ((__force gfp_t)___GFP_NOTRACK) /* Don't track with kmemcheck */

-#define __GFP_NO_KSWAPD ((__force gfp_t)___GFP_NO_KSWAPD)
#define __GFP_OTHER_NODE ((__force gfp_t)___GFP_OTHER_NODE) /* On behalf of other node */
#define __GFP_WRITE ((__force gfp_t)___GFP_WRITE) /* Allocator intends to dirty page */

/*
+ * A caller that is willing to wait may enter direct reclaim and will
+ * wake kswapd to reclaim pages in the background until the high
+ * watermark is met. A caller may wish to clear __GFP_DIRECT_RECLAIM to
+ * avoid unnecessary delays when a fallback option is available but
+ * still allow kswapd to reclaim in the background. The kswapd flag
+ * can be cleared when the reclaiming of pages would cause unnecessary
+ * disruption.
+ */
+#define __GFP_WAIT (__GFP_DIRECT_RECLAIM|__GFP_KSWAPD_RECLAIM)
+#define __GFP_DIRECT_RECLAIM ((__force gfp_t)___GFP_DIRECT_RECLAIM) /* Caller can reclaim */
+#define __GFP_KSWAPD_RECLAIM ((__force gfp_t)___GFP_KSWAPD_RECLAIM) /* kswapd can wake */
+
+/*
* This may seem redundant, but it's a way of annotating false positives vs.
* allocations that simply cannot be supported (e.g. page tables).
*/
#define __GFP_NOTRACK_FALSE_POSITIVE (__GFP_NOTRACK)

-#define __GFP_BITS_SHIFT 25 /* Room for N __GFP_FOO bits */
+#define __GFP_BITS_SHIFT 26 /* Room for N __GFP_FOO bits */
#define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))

-/* This equals 0, but use constants in case they ever change */
-#define GFP_NOWAIT (GFP_ATOMIC & ~__GFP_HIGH)
-/* GFP_ATOMIC means both !wait (__GFP_WAIT not set) and use emergency pool */
-#define GFP_ATOMIC (__GFP_HIGH)
+/*
+ * GFP_ATOMIC callers can not sleep, need the allocation to succeed.
+ * A lower watermark is applied to allow access to "atomic reserves"
+ */
+#define GFP_ATOMIC (__GFP_HIGH|__GFP_ATOMIC|__GFP_KSWAPD_RECLAIM)
+#define GFP_NOWAIT (__GFP_KSWAPD_RECLAIM)
#define GFP_NOIO (__GFP_WAIT)
#define GFP_NOFS (__GFP_WAIT | __GFP_IO)
#define GFP_KERNEL (__GFP_WAIT | __GFP_IO | __GFP_FS)
@@ -117,9 +132,9 @@ struct vm_area_struct;
#define GFP_HIGHUSER (GFP_USER | __GFP_HIGHMEM)
#define GFP_HIGHUSER_MOVABLE (GFP_HIGHUSER | __GFP_MOVABLE)
#define GFP_IOFS (__GFP_IO | __GFP_FS)
-#define GFP_TRANSHUGE (GFP_HIGHUSER_MOVABLE | __GFP_COMP | \
- __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN | \
- __GFP_NO_KSWAPD)
+#define GFP_TRANSHUGE ((GFP_HIGHUSER_MOVABLE | __GFP_COMP | \
+ __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN) & \
+ ~__GFP_KSWAPD_RECLAIM)

/* This mask makes up all the page movable related flags */
#define GFP_MOVABLE_MASK (__GFP_RECLAIMABLE|__GFP_MOVABLE)
@@ -161,6 +176,11 @@ static inline int gfpflags_to_migratetype(const gfp_t gfp_flags)
return (gfp_flags & GFP_MOVABLE_MASK) >> GFP_MOVABLE_SHIFT;
}

+static inline bool gfpflags_allows_blocking(const gfp_t gfp_flags)
+{
+ return gfp_flags & __GFP_DIRECT_RECLAIM;
+}
+
#ifdef CONFIG_HIGHMEM
#define OPT_ZONE_HIGHMEM ZONE_HIGHMEM
#else
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index d6cdd6e87d53..1086bfa3eb80 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -1109,7 +1109,7 @@ static inline int skb_cloned(const struct sk_buff *skb)

static inline int skb_unclone(struct sk_buff *skb, gfp_t pri)
{
- might_sleep_if(pri & __GFP_WAIT);
+ might_sleep_if(gfpflags_allows_blocking(pri));

if (skb_cloned(skb))
return pskb_expand_head(skb, 0, 0, pri);
@@ -1193,7 +1193,7 @@ static inline int skb_shared(const struct sk_buff *skb)
*/
static inline struct sk_buff *skb_share_check(struct sk_buff *skb, gfp_t pri)
{
- might_sleep_if(pri & __GFP_WAIT);
+ might_sleep_if(gfpflags_allows_blocking(pri));
if (skb_shared(skb)) {
struct sk_buff *nskb = skb_clone(skb, pri);

@@ -1229,7 +1229,7 @@ static inline struct sk_buff *skb_share_check(struct sk_buff *skb, gfp_t pri)
static inline struct sk_buff *skb_unshare(struct sk_buff *skb,
gfp_t pri)
{
- might_sleep_if(pri & __GFP_WAIT);
+ might_sleep_if(gfpflags_allows_blocking(pri));
if (skb_cloned(skb)) {
struct sk_buff *nskb = skb_copy(skb, pri);

diff --git a/include/net/sock.h b/include/net/sock.h
index f21f0708ec59..3ab94d6b0b56 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -2035,7 +2035,7 @@ struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp,
*/
static inline struct page_frag *sk_page_frag(struct sock *sk)
{
- if (sk->sk_allocation & __GFP_WAIT)
+ if (sk->sk_allocation & __GFP_DIRECT_RECLAIM)
return &current->task_frag;

return &sk->sk_frag;
diff --git a/include/trace/events/gfpflags.h b/include/trace/events/gfpflags.h
index d6fd8e5b14b7..dde6bf092c8a 100644
--- a/include/trace/events/gfpflags.h
+++ b/include/trace/events/gfpflags.h
@@ -20,7 +20,7 @@
{(unsigned long)GFP_ATOMIC, "GFP_ATOMIC"}, \
{(unsigned long)GFP_NOIO, "GFP_NOIO"}, \
{(unsigned long)__GFP_HIGH, "GFP_HIGH"}, \
- {(unsigned long)__GFP_WAIT, "GFP_WAIT"}, \
+ {(unsigned long)__GFP_ATOMIC, "GFP_ATOMIC"}, \
{(unsigned long)__GFP_IO, "GFP_IO"}, \
{(unsigned long)__GFP_COLD, "GFP_COLD"}, \
{(unsigned long)__GFP_NOWARN, "GFP_NOWARN"}, \
@@ -36,7 +36,8 @@
{(unsigned long)__GFP_RECLAIMABLE, "GFP_RECLAIMABLE"}, \
{(unsigned long)__GFP_MOVABLE, "GFP_MOVABLE"}, \
{(unsigned long)__GFP_NOTRACK, "GFP_NOTRACK"}, \
- {(unsigned long)__GFP_NO_KSWAPD, "GFP_NO_KSWAPD"}, \
+ {(unsigned long)__GFP_DIRECT_RECLAIM, "GFP_DIRECT_RECLAIM"}, \
+ {(unsigned long)__GFP_KSWAPD_RECLAIM, "GFP_KSWAPD_RECLAIM"}, \
{(unsigned long)__GFP_OTHER_NODE, "GFP_OTHER_NODE"} \
) : "GFP_NOWAIT"

diff --git a/kernel/audit.c b/kernel/audit.c
index f9e6065346db..6ab7a55dbdff 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -1357,16 +1357,16 @@ struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask,
if (unlikely(audit_filter_type(type)))
return NULL;

- if (gfp_mask & __GFP_WAIT) {
+ if (gfp_mask & __GFP_DIRECT_RECLAIM) {
if (audit_pid && audit_pid == current->pid)
- gfp_mask &= ~__GFP_WAIT;
+ gfp_mask &= ~__GFP_DIRECT_RECLAIM;
else
reserve = 0;
}

while (audit_backlog_limit
&& skb_queue_len(&audit_skb_queue) > audit_backlog_limit + reserve) {
- if (gfp_mask & __GFP_WAIT && audit_backlog_wait_time) {
+ if (gfp_mask & __GFP_DIRECT_RECLAIM && audit_backlog_wait_time) {
long sleep_time;

sleep_time = timeout_start + audit_backlog_wait_time - jiffies;
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 8acfbf773e06..9aa39f20f593 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -2738,7 +2738,7 @@ static void __lockdep_trace_alloc(gfp_t gfp_mask, unsigned long flags)
return;

/* no reclaim without waiting on it */
- if (!(gfp_mask & __GFP_WAIT))
+ if (!(gfp_mask & __GFP_DIRECT_RECLAIM))
return;

/* this guy won't enter reclaim */
diff --git a/kernel/smp.c b/kernel/smp.c
index 07854477c164..32ee47f6ac11 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -669,7 +669,7 @@ void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
cpumask_var_t cpus;
int cpu, ret;

- might_sleep_if(gfp_flags & __GFP_WAIT);
+ might_sleep_if(gfp_flags & __GFP_DIRECT_RECLAIM);

if (likely(zalloc_cpumask_var(&cpus, (gfp_flags|__GFP_NOWARN)))) {
preempt_disable();
diff --git a/lib/idr.c b/lib/idr.c
index 5335c43adf46..e5118fc82961 100644
--- a/lib/idr.c
+++ b/lib/idr.c
@@ -399,7 +399,7 @@ void idr_preload(gfp_t gfp_mask)
* allocation guarantee. Disallow usage from those contexts.
*/
WARN_ON_ONCE(in_interrupt());
- might_sleep_if(gfp_mask & __GFP_WAIT);
+ might_sleep_if(gfp_mask & __GFP_DIRECT_RECLAIM);

preempt_disable();

@@ -453,7 +453,7 @@ int idr_alloc(struct idr *idr, void *ptr, int start, int end, gfp_t gfp_mask)
struct idr_layer *pa[MAX_IDR_LEVEL + 1];
int id;

- might_sleep_if(gfp_mask & __GFP_WAIT);
+ might_sleep_if(gfp_mask & __GFP_DIRECT_RECLAIM);

/* sanity checks */
if (WARN_ON_ONCE(start < 0))
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index f9ebe1c82060..cc5fdc3fb734 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -188,7 +188,7 @@ radix_tree_node_alloc(struct radix_tree_root *root)
* preloading in the interrupt anyway as all the allocations have to
* be atomic. So just do normal allocation when in interrupt.
*/
- if (!(gfp_mask & __GFP_WAIT) && !in_interrupt()) {
+ if (!(gfp_mask & __GFP_DIRECT_RECLAIM) && !in_interrupt()) {
struct radix_tree_preload *rtp;

/*
@@ -249,7 +249,7 @@ radix_tree_node_free(struct radix_tree_node *node)
* with preemption not disabled.
*
* To make use of this facility, the radix tree must be initialised without
- * __GFP_WAIT being passed to INIT_RADIX_TREE().
+ * __GFP_DIRECT_RECLAIM being passed to INIT_RADIX_TREE().
*/
static int __radix_tree_preload(gfp_t gfp_mask)
{
@@ -286,12 +286,12 @@ static int __radix_tree_preload(gfp_t gfp_mask)
* with preemption not disabled.
*
* To make use of this facility, the radix tree must be initialised without
- * __GFP_WAIT being passed to INIT_RADIX_TREE().
+ * __GFP_DIRECT_RECLAIM being passed to INIT_RADIX_TREE().
*/
int radix_tree_preload(gfp_t gfp_mask)
{
/* Warn on non-sensical use... */
- WARN_ON_ONCE(!(gfp_mask & __GFP_WAIT));
+ WARN_ON_ONCE(!(gfp_mask & __GFP_DIRECT_RECLAIM));
return __radix_tree_preload(gfp_mask);
}
EXPORT_SYMBOL(radix_tree_preload);
@@ -303,7 +303,7 @@ EXPORT_SYMBOL(radix_tree_preload);
*/
int radix_tree_maybe_preload(gfp_t gfp_mask)
{
- if (gfp_mask & __GFP_WAIT)
+ if (gfp_mask & __GFP_DIRECT_RECLAIM)
return __radix_tree_preload(gfp_mask);
/* Preloading doesn't help anything with this gfp mask, skip it */
preempt_disable();
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index dac5bf59309d..2056d16807de 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -632,7 +632,7 @@ struct bdi_writeback *wb_get_create(struct backing_dev_info *bdi,
{
struct bdi_writeback *wb;

- might_sleep_if(gfp & __GFP_WAIT);
+ might_sleep_if(gfp & __GFP_DIRECT_RECLAIM);

if (!memcg_css->parent)
return &bdi->wb;
diff --git a/mm/dmapool.c b/mm/dmapool.c
index fd5fe4342e93..248f6e864a92 100644
--- a/mm/dmapool.c
+++ b/mm/dmapool.c
@@ -323,7 +323,7 @@ void *dma_pool_alloc(struct dma_pool *pool, gfp_t mem_flags,
size_t offset;
void *retval;

- might_sleep_if(mem_flags & __GFP_WAIT);
+ might_sleep_if(gfpflags_allows_blocking(mem_flags));

spin_lock_irqsave(&pool->lock, flags);
list_for_each_entry(page, &pool->page_list, page_list) {
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index acb93c554f6e..7155a556a8d4 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2268,7 +2268,7 @@ static int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
if (unlikely(task_in_memcg_oom(current)))
goto nomem;

- if (!(gfp_mask & __GFP_WAIT))
+ if (!gfpflags_allows_blocking(gfp_mask))
goto nomem;

mem_cgroup_events(mem_over_limit, MEMCG_MAX, 1);
@@ -2327,7 +2327,7 @@ static int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
css_get_many(&memcg->css, batch);
if (batch > nr_pages)
refill_stock(memcg, batch - nr_pages);
- if (!(gfp_mask & __GFP_WAIT))
+ if (!gfpflags_allows_blocking(gfp_mask))
goto done;
/*
* If the hierarchy is above the normal consumption range,
@@ -4696,8 +4696,8 @@ static int mem_cgroup_do_precharge(unsigned long count)
{
int ret;

- /* Try a single bulk charge without reclaim first */
- ret = try_charge(mc.to, GFP_KERNEL & ~__GFP_WAIT, count);
+ /* Try a single bulk charge without reclaim first, kswapd may wake */
+ ret = try_charge(mc.to, GFP_KERNEL & ~__GFP_DIRECT_RECLAIM, count);
if (!ret) {
mc.precharge += count;
return ret;
diff --git a/mm/mempool.c b/mm/mempool.c
index 2cc08de8b1db..bfd2a0dd0e18 100644
--- a/mm/mempool.c
+++ b/mm/mempool.c
@@ -317,13 +317,13 @@ void * mempool_alloc(mempool_t *pool, gfp_t gfp_mask)
gfp_t gfp_temp;

VM_WARN_ON_ONCE(gfp_mask & __GFP_ZERO);
- might_sleep_if(gfp_mask & __GFP_WAIT);
+ might_sleep_if(gfp_mask & __GFP_DIRECT_RECLAIM);

gfp_mask |= __GFP_NOMEMALLOC; /* don't allocate emergency reserves */
gfp_mask |= __GFP_NORETRY; /* don't loop in __alloc_pages */
gfp_mask |= __GFP_NOWARN; /* failures are OK */

- gfp_temp = gfp_mask & ~(__GFP_WAIT|__GFP_IO);
+ gfp_temp = gfp_mask & ~(__GFP_DIRECT_RECLAIM|__GFP_IO);

repeat_alloc:

@@ -346,7 +346,7 @@ void * mempool_alloc(mempool_t *pool, gfp_t gfp_mask)
}

/*
- * We use gfp mask w/o __GFP_WAIT or IO for the first round. If
+ * We use gfp mask w/o direct reclaim or IO for the first round. If
* alloc failed with that and @pool was empty, retry immediately.
*/
if (gfp_temp != gfp_mask) {
@@ -355,8 +355,8 @@ void * mempool_alloc(mempool_t *pool, gfp_t gfp_mask)
goto repeat_alloc;
}

- /* We must not sleep if !__GFP_WAIT */
- if (!(gfp_mask & __GFP_WAIT)) {
+ /* We must not sleep if !__GFP_DIRECT_RECLAIM */
+ if (!(gfp_mask & __GFP_DIRECT_RECLAIM)) {
spin_unlock_irqrestore(&pool->lock, flags);
return NULL;
}
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 94f2f6bdd6d5..ccd235d02923 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2143,7 +2143,7 @@ static bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
return false;
if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
return false;
- if (fail_page_alloc.ignore_gfp_wait && (gfp_mask & __GFP_WAIT))
+ if (fail_page_alloc.ignore_gfp_wait && (gfp_mask & (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM)))
return false;

return should_fail(&fail_page_alloc.attr, 1 << order);
@@ -2459,7 +2459,7 @@ void warn_alloc_failed(gfp_t gfp_mask, int order, const char *fmt, ...)
if (test_thread_flag(TIF_MEMDIE) ||
(current->flags & (PF_MEMALLOC | PF_EXITING)))
filter &= ~SHOW_MEM_FILTER_NODES;
- if (in_interrupt() || !(gfp_mask & __GFP_WAIT))
+ if (in_interrupt() || !(gfp_mask & __GFP_WAIT) || (gfp_mask & __GFP_ATOMIC))
filter &= ~SHOW_MEM_FILTER_NODES;

if (fmt) {
@@ -2710,7 +2710,6 @@ static inline int
gfp_to_alloc_flags(gfp_t gfp_mask)
{
int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
- const bool atomic = !(gfp_mask & (__GFP_WAIT | __GFP_NO_KSWAPD));

/* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH);
@@ -2719,11 +2718,11 @@ gfp_to_alloc_flags(gfp_t gfp_mask)
* The caller may dip into page reserves a bit more if the caller
* cannot run direct reclaim, or if the caller has realtime scheduling
* policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
- * set both ALLOC_HARDER (atomic == true) and ALLOC_HIGH (__GFP_HIGH).
+ * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH).
*/
alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH);

- if (atomic) {
+ if (gfp_mask & __GFP_ATOMIC) {
/*
* Not worth trying to allocate harder for __GFP_NOMEMALLOC even
* if it can't schedule.
@@ -2764,7 +2763,7 @@ static inline struct page *
__alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
struct alloc_context *ac)
{
- const gfp_t wait = gfp_mask & __GFP_WAIT;
+ bool can_direct_reclaim = gfp_mask & __GFP_DIRECT_RECLAIM;
struct page *page = NULL;
int alloc_flags;
unsigned long pages_reclaimed = 0;
@@ -2785,15 +2784,23 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
}

/*
+ * We also sanity check to catch abuse of atomic reserves being used by
+ * callers that are not in atomic context.
+ */
+ if (WARN_ON_ONCE((gfp_mask & (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM)) ==
+ (__GFP_ATOMIC|__GFP_DIRECT_RECLAIM)))
+ gfp_mask &= ~__GFP_ATOMIC;
+
+ /*
* If this allocation cannot block and it is for a specific node, then
* fail early. There's no need to wakeup kswapd or retry for a
* speculative node-specific allocation.
*/
- if (IS_ENABLED(CONFIG_NUMA) && (gfp_mask & __GFP_THISNODE) && !wait)
+ if (IS_ENABLED(CONFIG_NUMA) && (gfp_mask & __GFP_THISNODE) && !can_direct_reclaim)
goto nopage;

retry:
- if (!(gfp_mask & __GFP_NO_KSWAPD))
+ if (gfp_mask & __GFP_KSWAPD_RECLAIM)
wake_all_kswapds(order, ac);

/*
@@ -2836,8 +2843,8 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
}
}

- /* Atomic allocations - we can't balance anything */
- if (!wait) {
+ /* Caller is not willing to reclaim, we can't balance anything */
+ if (!can_direct_reclaim) {
/*
* All existing users of the deprecated __GFP_NOFAIL are
* blockable, so warn of any new users that actually allow this
@@ -2974,7 +2981,7 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,

lockdep_trace_alloc(gfp_mask);

- might_sleep_if(gfp_mask & __GFP_WAIT);
+ might_sleep_if(gfp_mask & __GFP_DIRECT_RECLAIM);

if (should_fail_alloc_page(gfp_mask, order))
return NULL;
diff --git a/mm/slab.c b/mm/slab.c
index 200e22412a16..a7bcbcc5692e 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1030,12 +1030,12 @@ static inline int cache_free_alien(struct kmem_cache *cachep, void *objp)
}

/*
- * Construct gfp mask to allocate from a specific node but do not invoke reclaim
- * or warn about failures.
+ * Construct gfp mask to allocate from a specific node but do not direct reclaim
+ * or warn about failures. kswapd may still wake to reclaim in the background.
*/
static inline gfp_t gfp_exact_node(gfp_t flags)
{
- return (flags | __GFP_THISNODE | __GFP_NOWARN) & ~__GFP_WAIT;
+ return (flags | __GFP_THISNODE | __GFP_NOWARN) & ~__GFP_DIRECT_RECLAIM;
}
#endif

@@ -2625,7 +2625,7 @@ static int cache_grow(struct kmem_cache *cachep,

offset *= cachep->colour_off;

- if (local_flags & __GFP_WAIT)
+ if (local_flags & __GFP_DIRECT_RECLAIM)
local_irq_enable();

/*
@@ -2655,7 +2655,7 @@ static int cache_grow(struct kmem_cache *cachep,

cache_init_objs(cachep, page);

- if (local_flags & __GFP_WAIT)
+ if (local_flags & __GFP_DIRECT_RECLAIM)
local_irq_disable();
check_irq_off();
spin_lock(&n->list_lock);
@@ -2669,7 +2669,7 @@ static int cache_grow(struct kmem_cache *cachep,
opps1:
kmem_freepages(cachep, page);
failed:
- if (local_flags & __GFP_WAIT)
+ if (local_flags & __GFP_DIRECT_RECLAIM)
local_irq_disable();
return 0;
}
@@ -2861,7 +2861,7 @@ static void *cache_alloc_refill(struct kmem_cache *cachep, gfp_t flags,
static inline void cache_alloc_debugcheck_before(struct kmem_cache *cachep,
gfp_t flags)
{
- might_sleep_if(flags & __GFP_WAIT);
+ might_sleep_if(flags & __GFP_DIRECT_RECLAIM);
#if DEBUG
kmem_flagcheck(cachep, flags);
#endif
@@ -3049,11 +3049,11 @@ static void *fallback_alloc(struct kmem_cache *cache, gfp_t flags)
*/
struct page *page;

- if (local_flags & __GFP_WAIT)
+ if (local_flags & __GFP_DIRECT_RECLAIM)
local_irq_enable();
kmem_flagcheck(cache, flags);
page = kmem_getpages(cache, local_flags, numa_mem_id());
- if (local_flags & __GFP_WAIT)
+ if (local_flags & __GFP_DIRECT_RECLAIM)
local_irq_disable();
if (page) {
/*
diff --git a/mm/slub.c b/mm/slub.c
index 816df0016555..b658a66ffce4 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1263,7 +1263,7 @@ static inline struct kmem_cache *slab_pre_alloc_hook(struct kmem_cache *s,
{
flags &= gfp_allowed_mask;
lockdep_trace_alloc(flags);
- might_sleep_if(flags & __GFP_WAIT);
+ might_sleep_if(gfpflags_allows_blocking(flags));

if (should_failslab(s->object_size, flags, s->flags))
return NULL;
@@ -1339,7 +1339,7 @@ static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)

flags &= gfp_allowed_mask;

- if (flags & __GFP_WAIT)
+ if (flags & __GFP_DIRECT_RECLAIM)
local_irq_enable();

flags |= s->allocflags;
@@ -1380,7 +1380,7 @@ static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
kmemcheck_mark_unallocated_pages(page, pages);
}

- if (flags & __GFP_WAIT)
+ if (flags & __GFP_DIRECT_RECLAIM)
local_irq_disable();
if (!page)
return NULL;
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 2faaa2976447..c6ce91b20c91 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1617,7 +1617,7 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
goto fail;
}
area->pages[i] = page;
- if (gfp_mask & __GFP_WAIT)
+ if (gfpflags_allows_blocking(gfp_mask))
cond_resched();
}

diff --git a/mm/vmscan.c b/mm/vmscan.c
index f1d8eae285f2..bc9ab358b77a 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -3768,7 +3768,7 @@ int zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
/*
* Do not scan if the allocation should not be delayed.
*/
- if (!(gfp_mask & __GFP_WAIT) || (current->flags & PF_MEMALLOC))
+ if (!gfpflags_allows_blocking(gfp_mask) || (current->flags & PF_MEMALLOC))
return ZONE_RECLAIM_NOSCAN;

/*
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index b6a19ca0f99e..6f025e2544de 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -414,7 +414,7 @@ struct sk_buff *__netdev_alloc_skb(struct net_device *dev, unsigned int len,
len += NET_SKB_PAD;

if ((len > SKB_WITH_OVERHEAD(PAGE_SIZE)) ||
- (gfp_mask & (__GFP_WAIT | GFP_DMA))) {
+ (gfp_mask & (__GFP_DIRECT_RECLAIM | GFP_DMA))) {
skb = __alloc_skb(len, gfp_mask, SKB_ALLOC_RX, NUMA_NO_NODE);
if (!skb)
goto skb_fail;
@@ -481,7 +481,7 @@ struct sk_buff *__napi_alloc_skb(struct napi_struct *napi, unsigned int len,
len += NET_SKB_PAD + NET_IP_ALIGN;

if ((len > SKB_WITH_OVERHEAD(PAGE_SIZE)) ||
- (gfp_mask & (__GFP_WAIT | GFP_DMA))) {
+ (gfp_mask & (__GFP_DIRECT_RECLAIM | GFP_DMA))) {
skb = __alloc_skb(len, gfp_mask, SKB_ALLOC_RX, NUMA_NO_NODE);
if (!skb)
goto skb_fail;
@@ -4452,7 +4452,7 @@ struct sk_buff *alloc_skb_with_frags(unsigned long header_len,
return NULL;

gfp_head = gfp_mask;
- if (gfp_head & __GFP_WAIT)
+ if (gfp_head & __GFP_DIRECT_RECLAIM)
gfp_head |= __GFP_REPEAT;

*errcode = -ENOBUFS;
@@ -4467,7 +4467,7 @@ struct sk_buff *alloc_skb_with_frags(unsigned long header_len,

while (order) {
if (npages >= 1 << order) {
- page = alloc_pages((gfp_mask & ~__GFP_WAIT) |
+ page = alloc_pages((gfp_mask & ~__GFP_DIRECT_RECLAIM) |
__GFP_COMP |
__GFP_NOWARN |
__GFP_NORETRY,
diff --git a/net/core/sock.c b/net/core/sock.c
index 193901d09757..02b705cc9eb3 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1879,8 +1879,10 @@ bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t gfp)

pfrag->offset = 0;
if (SKB_FRAG_PAGE_ORDER) {
- pfrag->page = alloc_pages((gfp & ~__GFP_WAIT) | __GFP_COMP |
- __GFP_NOWARN | __GFP_NORETRY,
+ /* Avoid direct reclaim but allow kswapd to wake */
+ pfrag->page = alloc_pages((gfp & ~__GFP_DIRECT_RECLAIM) |
+ __GFP_COMP | __GFP_NOWARN |
+ __GFP_NORETRY,
SKB_FRAG_PAGE_ORDER);
if (likely(pfrag->page)) {
pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER;
diff --git a/net/sctp/associola.c b/net/sctp/associola.c
index 197c3f59ecbf..c5fcdd6f85b7 100644
--- a/net/sctp/associola.c
+++ b/net/sctp/associola.c
@@ -1588,7 +1588,7 @@ int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
/* Set an association id for a given association */
int sctp_assoc_set_id(struct sctp_association *asoc, gfp_t gfp)
{
- bool preload = !!(gfp & __GFP_WAIT);
+ bool preload = !!(gfp & __GFP_DIRECT_RECLAIM);
int ret;

/* If the id is already assigned, keep it. */
--
2.4.6

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