On Thu, Sep 03, 2020 at 03:18:53PM +0300, Leon Romanovsky wrote: > From: Maor Gottlieb <maorg@xxxxxxxxxx> > > Remove the implementation of ib_umem_add_sg_table and instead > call to sg_alloc_table_append which already has the logic to > merge contiguous pages. > > Besides that it removes duplicated functionality, it reduces the > memory consumption of the SG table significantly. Prior to this > patch, the SG table was allocated in advance regardless consideration > of contiguous pages. > > In huge pages system of 2MB page size, without this change, the SG table > would contain x512 SG entries. > E.g. for 100GB memory registration: > > Number of entries Size > Before 26214400 600.0MB > After 51200 1.2MB > > Signed-off-by: Maor Gottlieb <maorg@xxxxxxxxxx> > Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxx> Looks sensible for now, but the real fix is of course to avoid the scatterlist here entirely, and provide a bvec based pin_user_pages_fast. I'll need to finally get that done..
