snowball/igloo-kernel.git/net/packet, branch u0

net: Use skb_checksum_start_offset()

2010-12-16T22:43:14+00:00

Replace skb->csum_start - skb_headroom(skb) with skb_checksum_start_offset(). Note for usb/smsc95xx: skb->data - skb->head == skb_headroom(skb). Signed-off-by: Michał Mirosław Signed-off-by: David S. Miller

af_packet: use swap() instead of the open coded macro XC()

2010-12-11T00:02:20+00:00

Signed-off-by: Changli Gao Signed-off-by: David S. Miller

af_packet: fix freeing pg_vec twice on error path

2010-12-08T18:43:41+00:00

It is introduced in: commit 0e3125c755445664f00ad036e4fc2cd32fd52877 Author: Neil Horman Date: Tue Nov 16 10:26:47 2010 -0800 packet: Enhance AF_PACKET implementation to not require high order contiguous memory allocation (v4) Signed-off-by: Changli Gao Signed-off-by: David S. Miller

af_packet: eliminate pgv_to_page on some arches

2010-12-08T18:43:41+00:00

Some arches don't need flush_dcache_page(), and don't implement it, so we can eliminate pgv_to_page() calls on those arches. Signed-off-by: Changli Gao Signed-off-by: David S. Miller

filter: constify sk_run_filter()

2010-12-08T18:30:34+00:00

sk_run_filter() doesnt write on skb, change its prototype to reflect this. Fix two af_packet comments. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

af_packet: remove pgv.flags

2010-12-06T20:59:07+00:00

As we can check if an address is vmalloc address with is_vmalloc_addr(), we remove pgv.flags. Then we may get more pg_vecs. Signed-off-by: Changli Gao Signed-off-by: David S. Miller

af_packet: use vmalloc_to_page() instead for the addresss returned by vmalloc()

2010-12-06T20:59:06+00:00

The following commit causes the pgv->buffer may point to the memory returned by vmalloc(). And we can't use virt_to_page() for the vmalloc address. This patch introduces a new inline function pgv_to_page(), which calls vmalloc_to_page() for the vmalloc address, and virt_to_page() for the __get_free_pages address. We used to increase page pointer to get the next page at the next page address, after Neil's patch, it is wrong, as the physical address may be not continuous. This patch also fixes this issue. commit 0e3125c755445664f00ad036e4fc2cd32fd52877 Author: Neil Horman Date: Tue Nov 16 10:26:47 2010 -0800 packet: Enhance AF_PACKET implementation to not require high order contiguous memory allocation (v4) Signed-off-by: Changli Gao Signed-off-by: David S. Miller

packet: use vzalloc()

2010-11-21T18:01:42+00:00

alloc_one_pg_vec_page() is supposed to return zeroed memory, so use vzalloc() instead of vmalloc() Signed-off-by: Eric Dumazet Cc: Neil Horman Acked-by: Neil Horman Signed-off-by: David S. Miller

filter: optimize sk_run_filter

2010-11-19T17:49:59+00:00

Remove pc variable to avoid arithmetic to compute fentry at each filter instruction. Jumps directly manipulate fentry pointer. As the last instruction of filter[] is guaranteed to be a RETURN, and all jumps are before the last instruction, we dont need to check filter bounds (number of instructions in filter array) at each iteration, so we remove it from sk_run_filter() params. On x86_32 remove f_k var introduced in commit 57fe93b374a6b871 (filter: make sure filters dont read uninitialized memory) Note : We could use a CONFIG_ARCH_HAS_{FEW|MANY}_REGISTERS in order to avoid too many ifdefs in this code. This helps compiler to use cpu registers to hold fentry and A accumulator. On x86_32, this saves 401 bytes, and more important, sk_run_filter() runs much faster because less register pressure (One less conditional branch per BPF instruction) # size net/core/filter.o net/core/filter_pre.o text data bss dec hex filename 2948 0 0 2948 b84 net/core/filter.o 3349 0 0 3349 d15 net/core/filter_pre.o on x86_64 : # size net/core/filter.o net/core/filter_pre.o text data bss dec hex filename 5173 0 0 5173 1435 net/core/filter.o 5224 0 0 5224 1468 net/core/filter_pre.o Signed-off-by: Eric Dumazet Acked-by: Changli Gao Signed-off-by: David S. Miller

packet: Enhance AF_PACKET implementation to not require high order contiguous memory allocation (v4)

2010-11-16T18:26:47+00:00

MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Version 4 of this patch. Change notes: 1) Removed extra memset. Didn't think kcalloc added a GFP_ZERO the way kzalloc did :) Summary: It was shown to me recently that systems under high load were driven very deep into swap when tcpdump was run. The reason this happened was because the AF_PACKET protocol has a SET_RINGBUFFER socket option that allows the user space application to specify how many entries an AF_PACKET socket will have and how large each entry will be. It seems the default setting for tcpdump is to set the ring buffer to 32 entries of 64 Kb each, which implies 32 order 5 allocation. Thats difficult under good circumstances, and horrid under memory pressure. I thought it would be good to make that a bit more usable. I was going to do a simple conversion of the ring buffer from contigous pages to iovecs, but unfortunately, the metadata which AF_PACKET places in these buffers can easily span a page boundary, and given that these buffers get mapped into user space, and the data layout doesn't easily allow for a change to padding between frames to avoid that, a simple iovec change is just going to break user space ABI consistency. So I've done this, I've added a three tiered mechanism to the af_packet set_ring socket option. It attempts to allocate memory in the following order: 1) Using __get_free_pages with GFP_NORETRY set, so as to fail quickly without digging into swap 2) Using vmalloc 3) Using __get_free_pages with GFP_NORETRY clear, causing us to try as hard as needed to get the memory The effect is that we don't disturb the system as much when we're under load, while still being able to conduct tcpdumps effectively. Tested successfully by me. Signed-off-by: Neil Horman Acked-by: Eric Dumazet Acked-by: Maciej Żenczykowski Reported-by: Maciej Żenczykowski Signed-off-by: David S. Miller