Commit da6bc57a authored by Michal Hocko's avatar Michal Hocko Committed by Linus Torvalds
Browse files

net: use kvmalloc with __GFP_REPEAT rather than open coded variant 

fq_alloc_node, alloc_netdev_mqs and netif_alloc* open code kmalloc with
vmalloc fallback.  Use the kvmalloc variant instead.  Keep the
__GFP_REPEAT flag based on explanation from Eric:

 "At the time, tests on the hardware I had in my labs showed that
  vmalloc() could deliver pages spread all over the memory and that was
  a small penalty (once memory is fragmented enough, not at boot time)"

The way how the code is constructed means, however, that we prefer to go
and hit the OOM killer before we fall back to the vmalloc for requests
<=32kB (with 4kB pages) in the current code.  This is rather disruptive
for something that can be achived with the fallback.  On the other hand
__GFP_REPEAT doesn't have any useful semantic for these requests.  So
the effect of this patch is that requests which fit into 32kB will fall
back to vmalloc easier now.

Link: http://lkml.kernel.org/r/20170306103327.2766-3-mhocko@kernel.org


Signed-off-by: default avatarMichal Hocko <mhocko@suse.com>
Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
Cc: Eric Dumazet <edumazet@google.com>
Cc: David Miller <davem@davemloft.net>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 752ade68

net/core/dev.c

+9 −15
Original line number Diff line number Diff line
@@ -7264,12 +7264,10 @@ static int netif_alloc_rx_queues(struct net_device *dev) 


	BUG_ON(count < 1);



	rx = kzalloc(sz, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);

	if (!rx) {

		rx = vzalloc(sz);

	rx = kvzalloc(sz, GFP_KERNEL | __GFP_REPEAT);

	if (!rx)

		return -ENOMEM;

	}



	dev->_rx = rx;



	for (i = 0; i < count; i++)
@@ -7306,12 +7304,10 @@ static int netif_alloc_netdev_queues(struct net_device *dev) 
	if (count < 1 || count > 0xffff)

		return -EINVAL;



	tx = kzalloc(sz, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);

	if (!tx) {

		tx = vzalloc(sz);

	tx = kvzalloc(sz, GFP_KERNEL | __GFP_REPEAT);

	if (!tx)

		return -ENOMEM;

	}



	dev->_tx = tx;



	netdev_for_each_tx_queue(dev, netdev_init_one_queue, NULL);
@@ -7845,9 +7841,7 @@ struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name, 
	/* ensure 32-byte alignment of whole construct */

	alloc_size += NETDEV_ALIGN - 1;



	p = kzalloc(alloc_size, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);

	if (!p)

		p = vzalloc(alloc_size);

	p = kvzalloc(alloc_size, GFP_KERNEL | __GFP_REPEAT);

	if (!p)

		return NULL;

net/sched/sch_fq.c

+1 −11
Original line number Diff line number Diff line
@@ -624,16 +624,6 @@ static void fq_rehash(struct fq_sched_data *q, 
	q->stat_gc_flows += fcnt;

}



static void *fq_alloc_node(size_t sz, int node)

{

	void *ptr;



	ptr = kmalloc_node(sz, GFP_KERNEL | __GFP_REPEAT | __GFP_NOWARN, node);

	if (!ptr)

		ptr = vmalloc_node(sz, node);

	return ptr;

}



static void fq_free(void *addr)

{

	kvfree(addr);
@@ -650,7 +640,7 @@ static int fq_resize(struct Qdisc *sch, u32 log) 
		return 0;



	/* If XPS was setup, we can allocate memory on right NUMA node */

	array = fq_alloc_node(sizeof(struct rb_root) << log,

	array = kvmalloc_node(sizeof(struct rb_root) << log, GFP_KERNEL | __GFP_REPEAT,

			      netdev_queue_numa_node_read(sch->dev_queue));

	if (!array)

		return -ENOMEM;

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