On Tue, May 27, 2025 at 08:32:55PM -0700, Mina Almasry wrote: > On Tue, May 27, 2025 at 7:29 PM Byungchul Park <byungchul@xxxxxx> wrote: > > > > To simplify struct page, the effort to separate its own descriptor from > > struct page is required and the work for page pool is on going. > > > > Use netmem descriptor and APIs for page pool in mt76 code. > > > > Signed-off-by: Byungchul Park <byungchul@xxxxxx> > > This patch looks fine to me... but this is converting 1 driver to > netmem. There are hundreds of other drivers in the tree. Are we > converting all of them to netmem...? > > The motivating reason for existing drivers to use netmem is because > it's an abstract memory type that lets the driver support dma-buf > memory and io_uring memory: > > https://www.kernel.org/doc/Documentation/networking/netmem.rst > > This driver does not use the page_pool, doesn't support dma-buf > memory, or io_uring memory. Moving it to netmem I think will add > overhead due to the netmem_is_net_iov checks while providing no > tangible benefit AFAICT. Is your long term plan to convert all drivers > to netmem? That maybe thousands of lines of code that need to be > touched :( > > > --- > > drivers/net/wireless/mediatek/mt76/dma.c | 6 ++--- > > drivers/net/wireless/mediatek/mt76/mt76.h | 12 +++++----- > > .../net/wireless/mediatek/mt76/sdio_txrx.c | 24 +++++++++---------- > > drivers/net/wireless/mediatek/mt76/usb.c | 10 ++++---- > > 4 files changed, 26 insertions(+), 26 deletions(-) > > > > diff --git a/drivers/net/wireless/mediatek/mt76/dma.c b/drivers/net/wireless/mediatek/mt76/dma.c > > index 35b4ec91979e..cceff435ec4a 100644 > > --- a/drivers/net/wireless/mediatek/mt76/dma.c > > +++ b/drivers/net/wireless/mediatek/mt76/dma.c > > @@ -820,10 +820,10 @@ mt76_add_fragment(struct mt76_dev *dev, struct mt76_queue *q, void *data, > > int nr_frags = shinfo->nr_frags; > > > > if (nr_frags < ARRAY_SIZE(shinfo->frags)) { > > - struct page *page = virt_to_head_page(data); > > - int offset = data - page_address(page) + q->buf_offset; > > + netmem_ref netmem = netmem_compound_head(virt_to_netmem(data)); > > It may be worth adding virt_to_head_netmem helper instead of doing > these 2 calls together everywhere. Sounds good. I will. Byungchul > > -- > Thanks, > Mina
