Mapping as little as 64GB can take more than 10 seconds,
triggering issues on kernels with CONFIG_PREEMPT_NONE=y.
ib_umem_get() already splits the work in 2MB units on x86_64,
adding a cond_resched() in the long-lasting loop is enough
to solve the issue.
Note that sg_alloc_table() can still use more than 100 ms,
which is also problematic. This might be addressed later
in ib_umem_add_sg_table(), adding new blocks in sgl
on demand.
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: Doug Ledford <dledford@xxxxxxxxxx>
Cc: Jason Gunthorpe <jgg@xxxxxxxx>
Cc: linux-rdma@xxxxxxxxxxxxxxx
---
drivers/infiniband/core/umem.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c
index 82455a1392f1d19c96ae956f0bd4e93e3a52d29c..831bff8d52e547834e9e04064127fbb280595126 100644
--- a/drivers/infiniband/core/umem.c
+++ b/drivers/infiniband/core/umem.c
@@ -261,6 +261,7 @@ struct ib_umem *ib_umem_get(struct ib_device *device, unsigned long addr,
sg = umem->sg_head.sgl;
while (npages) {
+ cond_resched();
ret = pin_user_pages_fast(cur_base,
min_t(unsigned long, npages,
PAGE_SIZE /
--
2.28.0.rc0.142.g3c755180ce-goog
