kernel/include/net/inet_frag.h, branch linux-4.1.y

percpu_counter: add @gfp to percpu_counter_init()

2014-09-08T00:51:29Z

Percpu allocator now supports allocation mask. Add @gfp to percpu_counter_init() so that !GFP_KERNEL allocation masks can be used with percpu_counters too. We could have left percpu_counter_init() alone and added percpu_counter_init_gfp(); however, the number of users isn't that high and introducing _gfp variants to all percpu data structures would be quite ugly, so let's just do the conversion. This is the one with the most users. Other percpu data structures are a lot easier to convert. This patch doesn't make any functional difference. Signed-off-by: Tejun Heo Acked-by: Jan Kara Acked-by: "David S. Miller" Cc: x86@kernel.org Cc: Jens Axboe Cc: "Theodore Ts'o" Cc: Alexander Viro Cc: Andrew Morton

inet: frags: use kmem_cache for inet_frag_queue

2014-08-02T22:31:31Z

Use kmem_cache to allocate/free inet_frag_queue objects since they're all the same size per inet_frags user and are alloced/freed in high volumes thus making it a perfect case for kmem_cache. Signed-off-by: Nikolay Aleksandrov Acked-by: Florian Westphal Signed-off-by: David S. Miller

inet: frags: enum the flag definitions and add descriptions

2014-08-02T22:31:31Z

Move the flags to an enum definion, swap FIRST_IN/LAST_IN to be in increasing order and add comments explaining each flag and the inet_frag_queue struct members. Signed-off-by: Nikolay Aleksandrov Signed-off-by: David S. Miller

inet: frags: rename last_in to flags

2014-08-02T22:31:31Z

The last_in field has been used to store various flags different from first/last frag in so give it a more descriptive name: flags. Signed-off-by: Nikolay Aleksandrov Signed-off-by: David S. Miller

inet: frag: use seqlock for hash rebuild

2014-07-28T05:34:36Z

rehash is rare operation, don't force readers to take the read-side rwlock. Instead, we only have to detect the (rare) case where the secret was altered while we are trying to insert a new inetfrag queue into the table. If it was changed, drop the bucket lock and recompute the hash to get the 'new' chain bucket that we have to insert into. Joint work with Nikolay Aleksandrov. Signed-off-by: Florian Westphal Signed-off-by: Nikolay Aleksandrov Signed-off-by: David S. Miller

inet: frag: remove periodic secret rebuild timer

2014-07-28T05:34:36Z

merge functionality into the eviction workqueue. Instead of rebuilding every n seconds, take advantage of the upper hash chain length limit. If we hit it, mark table for rebuild and schedule workqueue. To prevent frequent rebuilds when we're completely overloaded, don't rebuild more than once every 5 seconds. ipfrag_secret_interval sysctl is now obsolete and has been marked as deprecated, it still can be changed so scripts won't be broken but it won't have any effect. A comment is left above each unused secret_timer variable to avoid confusion. Joint work with Nikolay Aleksandrov. Signed-off-by: Florian Westphal Signed-off-by: Nikolay Aleksandrov Signed-off-by: David S. Miller

inet: frag: remove lru list

2014-07-28T05:34:36Z

no longer used. Signed-off-by: Florian Westphal Signed-off-by: David S. Miller

inet: frag: don't account number of fragment queues

2014-07-28T05:34:36Z

The 'nqueues' counter is protected by the lru list lock, once thats removed this needs to be converted to atomic counter. Given this isn't used for anything except for reporting it to userspace via /proc, just remove it. We still report the memory currently used by fragment reassembly queues. Signed-off-by: Florian Westphal Signed-off-by: David S. Miller

inet: frag: move eviction of queues to work queue

2014-07-28T05:34:35Z

When the high_thresh limit is reached we try to toss the 'oldest' incomplete fragment queues until memory limits are below the low_thresh value. This happens in softirq/packet processing context. This has two drawbacks: 1) processors might evict a queue that was about to be completed by another cpu, because they will compete wrt. resource usage and resource reclaim. 2) LRU list maintenance is expensive. But when constantly overloaded, even the 'least recently used' element is recent, so removing 'lru' queue first is not 'fairer' than removing any other fragment queue. This moves eviction out of the fast path: When the low threshold is reached, a work queue is scheduled which then iterates over the table and removes the queues that exceed the memory limits of the namespace. It sets a new flag called INET_FRAG_EVICTED on the evicted queues so the proper counters will get incremented when the queue is forcefully expired. When the high threshold is reached, no more fragment queues are created until we're below the limit again. The LRU list is now unused and will be removed in a followup patch. Joint work with Nikolay Aleksandrov. Suggested-by: Eric Dumazet Signed-off-by: Florian Westphal Signed-off-by: Nikolay Aleksandrov Signed-off-by: David S. Miller

inet: frag: move evictor calls into frag_find function

2014-07-28T05:34:35Z

First step to move eviction handling into a work queue. We lose two spots that accounted evicted fragments in MIB counters. Accounting will be restored since the upcoming work-queue evictor invokes the frag queue timer callbacks instead. Signed-off-by: Florian Westphal Signed-off-by: David S. Miller