kernel/linux.git/lib/rhashtable.c, branch v4.12.12

lib/rhashtable.c: simplify a strange allocation pattern

2017-05-09T00:15:12+00:00

alloc_bucket_locks allocation pattern is quite unusual. We are preferring vmalloc when CONFIG_NUMA is enabled. The rationale is that vmalloc will respect the memory policy of the current process and so the backing memory will get distributed over multiple nodes if the requester is configured properly. At least that is the intention, in reality rhastable is shrunk and expanded from a kernel worker so no mempolicy can be assumed. Let's just simplify the code and use kvmalloc helper, which is a transparent way to use kmalloc with vmalloc fallback, if the caller is allowed to block and use the flag otherwise. Link: http://lkml.kernel.org/r/20170306103032.2540-4-mhocko@kernel.org Signed-off-by: Michal Hocko Acked-by: Vlastimil Babka Cc: Tom Herbert Cc: Eric Dumazet Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

rhashtable: compact struct rhashtable_params

2017-05-01T20:22:40+00:00

By using smaller datatypes this (rather large) struct shrinks considerably (80 -> 48 bytes on x86_64). As this is embedded in other structs, this also rerduces size of several others, e.g. cls_fl_head or nft_hash. Signed-off-by: Florian Westphal Signed-off-by: David S. Miller

rhashtable: Do not lower max_elems when max_size is zero

2017-04-28T14:14:09+00:00

The commit 6d684e54690c ("rhashtable: Cap total number of entries to 2^31") breaks rhashtable users that do not set max_size. This is because when max_size is zero max_elems is also incorrectly set to zero instead of 2^31. This patch fixes it by only lowering max_elems when max_size is not zero. Fixes: 6d684e54690c ("rhashtable: Cap total number of entries to 2^31") Reported-by: Florian Fainelli Reported-by: kernel test robot Signed-off-by: Herbert Xu Signed-off-by: David S. Miller

rhashtable: Cap total number of entries to 2^31

2017-04-27T15:48:24+00:00

When max_size is not set or if it set to a sufficiently large value, the nelems counter can overflow. This would cause havoc with the automatic shrinking as it would then attempt to fit a huge number of entries into a tiny hash table. This patch fixes this by adding max_elems to struct rhashtable to cap the number of elements. This is set to 2^31 as nelems is not a precise count. This is sufficiently smaller than UINT_MAX that it should be safe. When max_size is set max_elems will be lowered to at most twice max_size as is the status quo. Signed-off-by: Herbert Xu Signed-off-by: David S. Miller

rhashtable: remove insecure_max_entries param

2017-04-26T18:39:24+00:00

no users in the tree, insecure_max_entries is always set to ht->p.max_size * 2 in rhtashtable_init(). Replace only spot that uses it with a ht->p.max_size check. Signed-off-by: Florian Westphal Signed-off-by: David S. Miller

rhashtable: remove insecure_elasticity

2017-04-18T17:49:14+00:00

commit 83e7e4ce9e93c3 ("mac80211: Use rhltable instead of rhashtable") removed the last user that made use of 'insecure_elasticity' parameter, i.e. the default of 16 is used everywhere. Replace it with a constant. Signed-off-by: Florian Westphal Signed-off-by: David S. Miller

sched/headers: Prepare to use instead of in

2017-03-02T07:42:38+00:00

We don't actually need the full rculist.h header in sched.h anymore, we will be able to include the smaller rcupdate.h header instead. But first update code that relied on the implicit header inclusion. Acked-by: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar

rhashtable: Fix RCU dereference annotation in rht_bucket_nested

2017-02-27T02:33:43+00:00

The current annotation is wrong as it says that we're only called under spinlock. In fact it should be marked as under either spinlock or RCU read lock. Fixes: da20420f83ea ("rhashtable: Add nested tables") Reported-by: Fengguang Wu Signed-off-by: Herbert Xu Signed-off-by: David S. Miller

rhashtable: Fix use before NULL check in bucket_table_free

2017-02-27T02:32:57+00:00

Dan Carpenter reported a use before NULL check bug in the function bucket_table_free. In fact we don't need the NULL check at all as no caller can provide a NULL argument. So this patch fixes this by simply removing it. Reported-by: Dan Carpenter Signed-off-by: Herbert Xu Signed-off-by: David S. Miller

rhashtable: Add nested tables

2017-02-17T17:28:35+00:00

This patch adds code that handles GFP_ATOMIC kmalloc failure on insertion. As we cannot use vmalloc, we solve it by making our hash table nested. That is, we allocate single pages at each level and reach our desired table size by nesting them. When a nested table is created, only a single page is allocated at the top-level. Lower levels are allocated on demand during insertion. Therefore for each insertion to succeed, only two (non-consecutive) pages are needed. After a nested table is created, a rehash will be scheduled in order to switch to a vmalloced table as soon as possible. Also, the rehash code will never rehash into a nested table. If we detect a nested table during a rehash, the rehash will be aborted and a new rehash will be scheduled. Signed-off-by: Herbert Xu Signed-off-by: David S. Miller