On Fri, Jul 31, 2020 at 10:17 AM Jason Gunthorpe <jgg@xxxxxxxxxx> wrote: > > On Wed, Jul 29, 2020 at 06:57:55PM -0700, Eric Dumazet wrote: > > 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. > > I have seen some patches in progress to do exactly this, the > motivation is to reduce the memory consumption if a lot of pages are > combined. Nice ;) > > > 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(+) > > Why [PATCH net] ? Sorry, I used a script that I normally use for net submissions, forgot to remove this tag ;) > > Anyhow, applied to rdma for-next Thanks ! > > Thanks, > Jason
