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* mm: page_frag: use __alloc_pages() to replace alloc_pages_node()Yunsheng Lin2024-11-111-3/+3
| | | | | | | | | | | | | | | | | | It seems there is about 24Bytes binary size increase for __page_frag_cache_refill() after refactoring in arm64 system with 64K PAGE_SIZE. By doing the gdb disassembling, It seems we can have more than 100Bytes decrease for the binary size by using __alloc_pages() to replace alloc_pages_node(), as there seems to be some unnecessary checking for nid being NUMA_NO_NODE, especially when page_frag is part of the mm system. CC: Andrew Morton <akpm@linux-foundation.org> CC: Linux-MM <linux-mm@kvack.org> Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com> Reviewed-by: Alexander Duyck <alexanderduyck@fb.com> Link: https://patch.msgid.link/20241028115343.3405838-8-linyunsheng@huawei.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* mm: page_frag: reuse existing space for 'size' and 'pfmemalloc'Yunsheng Lin2024-11-111-22/+48
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently there is one 'struct page_frag' for every 'struct sock' and 'struct task_struct', we are about to replace the 'struct page_frag' with 'struct page_frag_cache' for them. Before begin the replacing, we need to ensure the size of 'struct page_frag_cache' is not bigger than the size of 'struct page_frag', as there may be tens of thousands of 'struct sock' and 'struct task_struct' instances in the system. By or'ing the page order & pfmemalloc with lower bits of 'va' instead of using 'u16' or 'u32' for page size and 'u8' for pfmemalloc, we are able to avoid 3 or 5 bytes space waste. And page address & pfmemalloc & order is unchanged for the same page in the same 'page_frag_cache' instance, it makes sense to fit them together. After this patch, the size of 'struct page_frag_cache' should be the same as the size of 'struct page_frag'. CC: Andrew Morton <akpm@linux-foundation.org> CC: Linux-MM <linux-mm@kvack.org> Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com> Reviewed-by: Alexander Duyck <alexanderduyck@fb.com> Link: https://patch.msgid.link/20241028115343.3405838-7-linyunsheng@huawei.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* mm: page_frag: use initial zero offset for page_frag_alloc_align()Yunsheng Lin2024-11-111-23/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | We are about to use page_frag_alloc_*() API to not just allocate memory for skb->data, but also use them to do the memory allocation for skb frag too. Currently the implementation of page_frag in mm subsystem is running the offset as a countdown rather than count-up value, there may have several advantages to that as mentioned in [1], but it may have some disadvantages, for example, it may disable skb frag coalescing and more correct cache prefetching We have a trade-off to make in order to have a unified implementation and API for page_frag, so use a initial zero offset in this patch, and the following patch will try to make some optimization to avoid the disadvantages as much as possible. 1. https://lore.kernel.org/all/f4abe71b3439b39d17a6fb2d410180f367cadf5c.camel@gmail.com/ CC: Andrew Morton <akpm@linux-foundation.org> CC: Linux-MM <linux-mm@kvack.org> Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com> Reviewed-by: Alexander Duyck <alexanderduyck@fb.com> Link: https://patch.msgid.link/20241028115343.3405838-4-linyunsheng@huawei.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* mm: move the page fragment allocator from page_alloc into its own fileYunsheng Lin2024-11-111-0/+145
Inspired by [1], move the page fragment allocator from page_alloc into its own c file and header file, as we are about to make more change for it to replace another page_frag implementation in sock.c As this patchset is going to replace 'struct page_frag' with 'struct page_frag_cache' in sched.h, including page_frag_cache.h in sched.h has a compiler error caused by interdependence between mm_types.h and mm.h for asm-offsets.c, see [2]. So avoid the compiler error by moving 'struct page_frag_cache' to mm_types_task.h as suggested by Alexander, see [3]. 1. https://lore.kernel.org/all/20230411160902.4134381-3-dhowells@redhat.com/ 2. https://lore.kernel.org/all/15623dac-9358-4597-b3ee-3694a5956920@gmail.com/ 3. https://lore.kernel.org/all/CAKgT0UdH1yD=LSCXFJ=YM_aiA4OomD-2wXykO42bizaWMt_HOA@mail.gmail.com/ CC: David Howells <dhowells@redhat.com> CC: Linux-MM <linux-mm@kvack.org> Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com> Acked-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Alexander Duyck <alexanderduyck@fb.com> Link: https://patch.msgid.link/20241028115343.3405838-3-linyunsheng@huawei.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>