From d9b2938aabf757da2d40153489b251d4fc3fdd18 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 27 Aug 2014 20:49:34 -0700 Subject: net: attempt a single high order allocation In commit ed98df3361f0 ("net: use __GFP_NORETRY for high order allocations") we tried to address one issue caused by order-3 allocations. We still observe high latencies and system overhead in situations where compaction is not successful. Instead of trying order-3, order-2, and order-1, do a single order-3 best effort and immediately fallback to plain order-0. This mimics slub strategy to fallback to slab min order if the high order allocation used for performance failed. Order-3 allocations give a performance boost only if they can be done without recurring and expensive memory scan. Quoting David : The page allocator relies on synchronous (sync light) memory compaction after direct reclaim for allocations that don't retry and deferred compaction doesn't work with this strategy because the allocation order is always decreasing from the previous failed attempt. This means sync light compaction will always be encountered if memory cannot be defragmented or reclaimed several times during the skb_page_frag_refill() iteration. Signed-off-by: Eric Dumazet Acked-by: David Rientjes Signed-off-by: David S. Miller --- net/core/sock.c | 30 ++++++++++++++++-------------- 1 file changed, 16 insertions(+), 14 deletions(-) (limited to 'net/core/sock.c') diff --git a/net/core/sock.c b/net/core/sock.c index 2714811afbd8..29870571c42f 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1822,6 +1822,9 @@ struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len, order); if (page) goto fill_page; + /* Do not retry other high order allocations */ + order = 1; + max_page_order = 0; } order--; } @@ -1869,10 +1872,8 @@ EXPORT_SYMBOL(sock_alloc_send_skb); * no guarantee that allocations succeed. Therefore, @sz MUST be * less or equal than PAGE_SIZE. */ -bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t prio) +bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t gfp) { - int order; - if (pfrag->page) { if (atomic_read(&pfrag->page->_count) == 1) { pfrag->offset = 0; @@ -1883,20 +1884,21 @@ bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t prio) put_page(pfrag->page); } - order = SKB_FRAG_PAGE_ORDER; - do { - gfp_t gfp = prio; - - if (order) - gfp |= __GFP_COMP | __GFP_NOWARN | __GFP_NORETRY; - pfrag->page = alloc_pages(gfp, order); + pfrag->offset = 0; + if (SKB_FRAG_PAGE_ORDER) { + pfrag->page = alloc_pages(gfp | __GFP_COMP | + __GFP_NOWARN | __GFP_NORETRY, + SKB_FRAG_PAGE_ORDER); if (likely(pfrag->page)) { - pfrag->offset = 0; - pfrag->size = PAGE_SIZE << order; + pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER; return true; } - } while (--order >= 0); - + } + pfrag->page = alloc_page(gfp); + if (likely(pfrag->page)) { + pfrag->size = PAGE_SIZE; + return true; + } return false; } EXPORT_SYMBOL(skb_page_frag_refill); -- cgit v1.2.2 From e793c0f70e9bdf4a2e71c151a1a3cf85c4db92ad Mon Sep 17 00:00:00 2001 From: Masanari Iida Date: Thu, 4 Sep 2014 23:44:36 +0900 Subject: net: treewide: Fix typo found in DocBook/networking.xml This patch fix spelling typo found in DocBook/networking.xml. It is because the neworking.xml is generated from comments in the source, I have to fix typo in comments within the source. Signed-off-by: Masanari Iida Acked-by: Randy Dunlap Signed-off-by: David S. Miller --- net/core/sock.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'net/core/sock.c') diff --git a/net/core/sock.c b/net/core/sock.c index 29870571c42f..d372b4bd3f99 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -166,7 +166,7 @@ EXPORT_SYMBOL(sk_ns_capable); /** * sk_capable - Socket global capability test * @sk: Socket to use a capability on or through - * @cap: The global capbility to use + * @cap: The global capability to use * * Test to see if the opener of the socket had when the socket was * created and the current process has the capability @cap in all user @@ -183,7 +183,7 @@ EXPORT_SYMBOL(sk_capable); * @sk: Socket to use a capability on or through * @cap: The capability to use * - * Test to see if the opener of the socket had when the socke was created + * Test to see if the opener of the socket had when the socket was created * and the current process has the capability @cap over the network namespace * the socket is a member of. */ -- cgit v1.2.2 From 82d5e2b8b466d5bfc7c6278a7c04a53b9b287673 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 8 Sep 2014 04:00:00 -0700 Subject: net: fix skb_page_frag_refill() kerneldoc In commit d9b2938aabf7 ("net: attempt a single high order allocation) I forgot to update kerneldoc, as @prio parameter was renamed to @gfp Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/core/sock.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/core/sock.c') diff --git a/net/core/sock.c b/net/core/sock.c index d372b4bd3f99..9c3f823e76a9 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1866,7 +1866,7 @@ EXPORT_SYMBOL(sock_alloc_send_skb); * skb_page_frag_refill - check that a page_frag contains enough room * @sz: minimum size of the fragment we want to get * @pfrag: pointer to page_frag - * @prio: priority for memory allocation + * @gfp: priority for memory allocation * * Note: While this allocator tries to use high order pages, there is * no guarantee that allocations succeed. Therefore, @sz MUST be -- cgit v1.2.2