Commit 3dc2f209 authored by ZhangPeng's avatar ZhangPeng Committed by Christoph Hellwig
Browse files

swiotlb: check alloc_size before the allocation of a new memory pool 



The allocation request for swiotlb contiguous memory greater than
128*2KB cannot be fulfilled because it exceeds the maximum contiguous
memory limit. If the swiotlb memory we allocate is larger than 128*2KB,
swiotlb_find_slots() will still schedule the allocation of a new memory
pool, which will increase memory overhead.

Fix it by adding a check with alloc_size no more than 128*2KB before
scheduling the allocation of a new memory pool in swiotlb_find_slots().

Signed-off-by: default avatarZhangPeng <zhangpeng362@huawei.com>
Reviewed-by: default avatarPetr Tesarik <petr.tesarik1@huawei-partners.com>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
parent b07bc234

kernel/dma/swiotlb.c

+3 −0
Original line number Diff line number Diff line
@@ -1136,6 +1136,9 @@ static int swiotlb_find_slots(struct device *dev, phys_addr_t orig_addr, 
	int cpu, i;

	int index;



	if (alloc_size > IO_TLB_SEGSIZE * IO_TLB_SIZE)

		return -1;



	cpu = raw_smp_processor_id();

	for (i = 0; i < default_nareas; ++i) {

		index = swiotlb_search_area(dev, cpu, i, orig_addr, alloc_size,