| Message ID | 20241217105659.2215649-1-yajun.deng@linux.dev (mailing list archive) |
|---|---|
| State | Rejected |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net-next] sock: make SKB_FRAG_PAGE_ORDER equal to PAGE_ALLOC_COSTLY_ORDER | expand |
On Tue, Dec 17, 2024 at 11:56 AM Yajun Deng <yajun.deng@linux.dev> wrote: > > The SKB_FRAG_PAGE_ORDER will be 3 if PAGE_SIZE is 4096, and less than 3 > if it is not. So it will increase the number of memory allocations if > PAGE_SIZE is greater than 4096. > > alloc_pages() only relates to the order, if an order is less than or equal > to PAGE_ALLOC_COSTLY_ORDER, it will get the page from rmqueue_pcplist() in > rmqueue(). So there's no need for the order to be less than > PAGE_ALLOC_COSTLY_ORDER. > > To decrease the number of memory allocations, make SKB_FRAG_PAGE_ORDER > equal to PAGE_ALLOC_COSTLY_ORDER even if PAGE_SIZE isn't 4096. > > Signed-off-by: Yajun Deng <yajun.deng@linux.dev> > --- > include/net/sock.h | 2 +- > net/core/sock.c | 3 +-- > 2 files changed, 2 insertions(+), 3 deletions(-) > > diff --git a/include/net/sock.h b/include/net/sock.h > index 7464e9f9f47c..a33645226577 100644 > --- a/include/net/sock.h > +++ b/include/net/sock.h > @@ -2853,7 +2853,7 @@ extern __u32 sysctl_rmem_max; > extern __u32 sysctl_wmem_default; > extern __u32 sysctl_rmem_default; > > -#define SKB_FRAG_PAGE_ORDER get_order(32768) We do not want to allow some programs to work on arches with 64K page sizes, and not work on 4K page sizes. Please post your precise use case.
diff --git a/include/net/sock.h b/include/net/sock.h index 7464e9f9f47c..a33645226577 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -2853,7 +2853,7 @@ extern __u32 sysctl_rmem_max; extern __u32 sysctl_wmem_default; extern __u32 sysctl_rmem_default; -#define SKB_FRAG_PAGE_ORDER get_order(32768) +#define SKB_FRAG_PAGE_ORDER PAGE_ALLOC_COSTLY_ORDER DECLARE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key); static inline int sk_get_wmem0(const struct sock *sk, const struct proto *proto) diff --git a/net/core/sock.c b/net/core/sock.c index 74729d20cd00..0db306f4216c 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -3014,8 +3014,7 @@ bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t gfp) } pfrag->offset = 0; - if (SKB_FRAG_PAGE_ORDER && - !static_branch_unlikely(&net_high_order_alloc_disable_key)) { + if (!static_branch_unlikely(&net_high_order_alloc_disable_key)) { /* Avoid direct reclaim but allow kswapd to wake */ pfrag->page = alloc_pages((gfp & ~__GFP_DIRECT_RECLAIM) | __GFP_COMP | __GFP_NOWARN |
The SKB_FRAG_PAGE_ORDER will be 3 if PAGE_SIZE is 4096, and less than 3 if it is not. So it will increase the number of memory allocations if PAGE_SIZE is greater than 4096. alloc_pages() only relates to the order, if an order is less than or equal to PAGE_ALLOC_COSTLY_ORDER, it will get the page from rmqueue_pcplist() in rmqueue(). So there's no need for the order to be less than PAGE_ALLOC_COSTLY_ORDER. To decrease the number of memory allocations, make SKB_FRAG_PAGE_ORDER equal to PAGE_ALLOC_COSTLY_ORDER even if PAGE_SIZE isn't 4096. Signed-off-by: Yajun Deng <yajun.deng@linux.dev> --- include/net/sock.h | 2 +- net/core/sock.c | 3 +-- 2 files changed, 2 insertions(+), 3 deletions(-)