linux_dsm_epyc7002/include
Herbert Xu 07ee0722bf rhashtable: Add cap on number of elements in hash table
We currently have no limit on the number of elements in a hash table.
This is a problem because some users (tipc) set a ceiling on the
maximum table size and when that is reached the hash table may
degenerate.  Others may encounter OOM when growing and if we allow
insertions when that happens the hash table perofrmance may also
suffer.

This patch adds a new paramater insecure_max_entries which becomes
the cap on the table.  If unset it defaults to max_size * 2.  If
it is also zero it means that there is no cap on the number of
elements in the table.  However, the table will grow whenever the
utilisation hits 100% and if that growth fails, you will get ENOMEM
on insertion.

As allowing oversubscription is potentially dangerous, the name
contains the word insecure.

Note that the cap is not a hard limit.  This is done for performance
reasons as enforcing a hard limit will result in use of atomic ops
that are heavier than the ones we currently use.

The reasoning is that we're only guarding against a gross over-
subscription of the table, rather than a small breach of the limit.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-16 18:08:26 -04:00
..
acpi ACPICA: remove duplicate u8 typedef 2015-04-28 23:58:54 +02:00
asm-generic TTY/Serial patches for 4.1-rc1 2015-04-21 09:33:10 -07:00
clocksource
crypto Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2015-04-15 10:42:15 -07:00
drm Merge tag 'topic/drm-misc-2015-04-15' of git://anongit.freedesktop.org/drm-intel into drm-next 2015-04-16 08:34:24 +10:00
dt-bindings Merge branch 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma 2015-04-24 09:49:37 -07:00
keys
kvm KVM/ARM changes for v4.1: 2015-04-07 18:09:20 +02:00
linux rhashtable: Add cap on number of elements in hash table 2015-05-16 18:08:26 -04:00
math-emu
media Merge branch 'patchwork' into v4l_for_linus 2015-04-21 06:12:35 -03:00
memory
misc
net We have only a few fixes right now: 2015-05-04 16:00:55 -04:00
pcmcia
ras
rdma IB/core: Fix unaligned accesses 2015-05-05 13:21:27 -04:00
rxrpc RxRPC: Handle VERSION Rx protocol packets 2015-04-01 16:31:26 +01:00
scsi SCSI: add 1024 max sectors black list flag 2015-04-27 09:38:06 -07:00
soc
sound ASoC: Fixes for v4.1 2015-04-30 19:08:06 +02:00
target Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2015-04-24 10:22:09 -07:00
trace Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2015-04-26 17:22:07 -07:00
uapi Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf 2015-05-16 16:40:22 -04:00
video fbdev changes for v4.1 2015-04-20 15:16:25 -07:00
xen xen: Suspend ticks on all CPUs during suspend 2015-04-29 17:10:05 +01:00
Kbuild