Commit 33e5c765 authored by Trond Myklebust's avatar Trond Myklebust
Browse files

NFS: Fix memory allocation in rpc_malloc() 



When in a low memory situation, we do want rpciod to kick off direct
reclaim in the case where that helps, however we don't want it looping
forever in mempool_alloc().
So first try allocating from the slab using GFP_KERNEL | __GFP_NORETRY,
and then fall back to a GFP_NOWAIT allocation from the mempool.

Ditto for rpc_alloc_task()

Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
parent d0afde5f

include/linux/sunrpc/sched.h

+1 −0
Original line number Diff line number Diff line
@@ -262,6 +262,7 @@ void rpc_destroy_mempool(void); 
extern struct workqueue_struct *rpciod_workqueue;

extern struct workqueue_struct *xprtiod_workqueue;

void		rpc_prepare_task(struct rpc_task *task);

gfp_t		rpc_task_gfp_mask(void);



static inline int rpc_wait_for_completion_task(struct rpc_task *task)

{

net/sunrpc/sched.c

+14 −7
Original line number Diff line number Diff line
@@ -57,6 +57,13 @@ struct workqueue_struct *rpciod_workqueue __read_mostly; 
struct workqueue_struct *xprtiod_workqueue __read_mostly;

EXPORT_SYMBOL_GPL(xprtiod_workqueue);



gfp_t rpc_task_gfp_mask(void)

{

	if (current->flags & PF_WQ_WORKER)

		return GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN;

	return GFP_KERNEL;

}



unsigned long

rpc_task_timeout(const struct rpc_task *task)

{
@@ -1030,15 +1037,15 @@ int rpc_malloc(struct rpc_task *task) 
	struct rpc_rqst *rqst = task->tk_rqstp;

	size_t size = rqst->rq_callsize + rqst->rq_rcvsize;

	struct rpc_buffer *buf;

	gfp_t gfp = GFP_KERNEL;



	if (RPC_IS_ASYNC(task))

		gfp = GFP_NOWAIT | __GFP_NOWARN;

	gfp_t gfp = rpc_task_gfp_mask();



	size += sizeof(struct rpc_buffer);

	if (size <= RPC_BUFFER_MAXSIZE)

		buf = mempool_alloc(rpc_buffer_mempool, gfp);

	else

	if (size <= RPC_BUFFER_MAXSIZE) {

		buf = kmem_cache_alloc(rpc_buffer_slabp, gfp);

		/* Reach for the mempool if dynamic allocation fails */

		if (!buf && RPC_IS_ASYNC(task))

			buf = mempool_alloc(rpc_buffer_mempool, GFP_NOWAIT);

	} else

		buf = kmalloc(size, gfp);



	if (!buf)