This "feature" is unused, undocumented, and untested and so doesn't
really belong. A patch is under development to properly implement
support for detecting when a search gets diverted down a different
chain, which the common purpose of nulls markers.
This patch actually fixes a bug too. The table resizing allows a
table to grow to 2^31 buckets, but the hash is truncated to 27 bits -
any growth beyond 2^27 is wasteful an ineffective.
This patch results in NULLS_MARKER(0) being used for all chains,
and leaves the use of rht_is_a_null() to test for it.
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
print_ht in rhashtable_test calls rht_dereference() with neither
RCU protection or the mutex. This triggers an RCU warning.
So take the mutex to silence the warning.
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Tries to insert duplicates in the middle of bucket's chain:
bucket 1: [[val 21 (tid=1)]] -> [[ val 1 (tid=2), val 1 (tid=0) ]]
Reuses tid to distinguish the elements insertion order.
Signed-off-by: Paul Blakey <paulb@mellanox.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Most callers of rhashtable_walk_start don't care about a resize event
which is indicated by a return value of -EAGAIN. So calls to
rhashtable_walk_start are wrapped wih code to ignore -EAGAIN. Something
like this is common:
ret = rhashtable_walk_start(rhiter);
if (ret && ret != -EAGAIN)
goto out;
Since zero and -EAGAIN are the only possible return values from the
function this check is pointless. The condition never evaluates to true.
This patch changes rhashtable_walk_start to return void. This simplifies
code for the callers that ignore -EAGAIN. For the few cases where the
caller cares about the resize event, particularly where the table can be
walked in mulitple parts for netlink or seq file dump, the function
rhashtable_walk_start_check has been added that returns -EAGAIN on a
resize event.
Signed-off-by: Tom Herbert <tom@quantonium.net>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
kbuild test robot reported a section mismatch warning w. gcc 4.x:
WARNING: lib/test_rhashtable.o(.text+0x139e):
Section mismatch in reference from the function rhltable_insert.clone.3() to the variable .init.data:rhlt
so remove this annotation.
Fixes: cdd4de372e ("test_rhashtable: add test case for rhl_table interface")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
also test rhltable. rhltable remove operations are slow as
deletions require a list walk, thus test with 1/16th of the given
entry count number to get a run duration similar to rhashtable one.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
add a test that tries to insert more than max_size elements.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
pass the entries to test as an argument instead.
Followup patch will add an rhlist test case; rhlist delete opererations
are slow so we need to use a smaller number to test it.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
I forgot one spot when introducing struct test_obj_val.
Fixes: e859afe1ee ("lib: test_rhashtable: fix for large entry counts")
Reported by: kernel test robot <fengguang.wu@intel.com>
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>
During concurrent access testing, threadfunc() concatenated thread ID
and object index to create a unique key like so:
| tdata->objs[i].value = (tdata->id << 16) | i;
This breaks if a user passes an entries parameter of 64k or higher,
since 'i' might use more than 16 bits then. Effectively, this will lead
to duplicate keys in the table.
Fix the problem by introducing a struct holding object and thread ID and
using that as key instead of a single integer type field.
Fixes: f4a3e90ba5 ("rhashtable-test: extend to test concurrency")
Reported by: Manuel Messner <mm@skelett.io>
Signed-off-by: Phil Sutter <phil@nwl.cc>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Looks like a simple copy'n'paste error.
Fixes: 1aa661f5c3 ("rhashtable-test: Measure time to insert, remove & traverse entries")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>
In certain cases, the 802.11 mesh pathtable code wants to
iterate over all of the entries in the forwarding table from
the receive path, which is inside an RCU read-side critical
section. Enable walks inside atomic sections by allowing
GFP_ATOMIC allocations for the walker state.
Change all existing callsites to pass in GFP_KERNEL.
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: Bob Copeland <me@bobcopeland.com>
[also adjust gfs2/glock.c and rhashtable tests]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
This is rather a hack to expose the current issue with rhashtable to
under high pressure sometimes return -ENOMEM even though system memory
is not exhausted and a consecutive insert may succeed.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>
A maximum table size of 64k entries is insufficient for the multiple
threads test even in default configuration (10 threads * 50000 objects =
500000 objects in total). Since we know how many objects will be
inserted, calculate the max size unless overridden by parameter.
Note that specifying the exact number of objects upon table init won't
suffice as that value is being rounded down to the next power of two -
anticipate this by rounding up to the next power of two in beforehand.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>
After adding cond_resched() calls to threadfunc(), a surprisingly high
rate of insert failures occurred probably due to table resizes getting a
better chance to run in background. To not soften up the remaining
tests, retry inserts until they either succeed or fail permanently.
Also change the non-threaded test to retry insert operations, too.
Suggested-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>
This should fix for soft lockup bugs triggered on slow systems.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>
After having tested insertion, lookup, table walk and removal, spawn a
number of threads running operations on the same rhashtable. Each of
them will:
1) insert it's own set of objects,
2) lookup every successfully inserted object and finally
3) remove objects in several rounds until all of them have been removed,
making sure the remaining ones are still found after each round.
This should put a good amount of load onto the system and due to
synchronising thread startup via two semaphores also extensive
concurrent table access.
The default number of ten threads returned within half a second on my
local VM with two cores. Running 200 threads took about four seconds. If
slow systems suffer too much from this though, the default could be
lowered or even set to zero so this extended test does not run at all by
default.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Depending on system speed, the large lookup/insert/delete loops of the testsuite can
take a considerable amount of time to complete causing watchdog warnings to appear.
Allow other tasks to be scheduled throughout the loops.
Reported-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
A 64bit division went in unnoticed. Use do_div() to accomodate
non 64bit architectures.
Reported-by: kbuild test robot
Fixes: 1aa661f5c3 ("rhashtable-test: Measure time to insert, remove & traverse entries")
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Account for failed inserts due to memory pressure or EBUSY and
ignore failed entries during the consistency check.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
As resizes may continue to run in the background, use walker to
ensure we see all entries. Also print the encountered number
of rehashes queued up while traversing.
This may lead to warnings due to entries being seen multiple
times. We consider them non-fatal.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
By far the most expensive part of the selftest was the allocation
of entries. Using a static array allows to measure the rhashtable
operations.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
This only blows up the size of the test structure for no gain
in test coverage. Reduces size of test_obj from 24 to 16 bytes.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
NeilBrown
Kees Cook
Paul Blakey
Tom Herbert
Florian Westphal
Phil Sutter
Bob Copeland
Thomas Graf