On Wed, Jan 11, 2023 at 04:25:46PM +0800, Yunsheng Lin wrote:
On 2023/1/11 12:21, Matthew Wilcox (Oracle) wrote:
quoted
The MM subsystem is trying to reduce struct page to a single pointer.
The first step towards that is splitting struct page by its individual
users, as has already been done with folio and slab. This patchset does
that for netmem which is used for page pools.
As page pool is only used for rx side in the net stack depending on the
driver, a lot more memory for the net stack is from page_frag_alloc_align(),
kmem cache, etc.
naming it netmem seems a little overkill, perhaps a more specific name for
the page pool? such as pp_cache.
@Jesper & Ilias
Any better idea?
And it seem some API may need changing too, as we are not pooling 'pages'
now.
I raised the question of naming in v1, six weeks ago, and nobody had
any better names. Seems a little unfair to ignore the question at first
and then bring it up now. I'd hate to miss the merge window because of
a late-breaking major request like this.
https://lore.kernel.org/netdev/20221130220803.3657490-1-willy@infradead.org/ (local)
I'd like to understand what we think we'll do in networking when we trim
struct page down to a single pointer, All these usages that aren't from
page_pool -- what information does networking need to track per-allocation?
Would it make sense for the netmem to describe all memory used by the
networking stack, and have allocators other than page_pool also return
netmem, or does the normal usage of memory in the net stack not need to
track that information?
quoted
Matthew Wilcox (Oracle) (26):
netmem: Create new type
netmem: Add utility functions
page_pool: Add netmem_set_dma_addr() and netmem_get_dma_addr()
page_pool: Convert page_pool_release_page() to
page_pool_release_netmem()
page_pool: Start using netmem in allocation path.
^
nit: there is a '.' at the end of patch titile.
Thanks, I'll fix that for v4.