Re: [PATCH] lib: test_rhashtable: fix for large entry counts
From: Herbert Xu <herbert@gondor.apana.org.au>
Date: 2017-07-24 03:19:15
On Fri, Jul 21, 2017 at 04:51:31PM +0200, Phil Sutter wrote:
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: f4a3e90ba5739 ("rhashtable-test: extend to test concurrency")
Reported by: Manuel Messner [off-list ref]
Signed-off-by: Phil Sutter <phil@nwl.cc>Acked-by: Herbert Xu <herbert@gondor.apana.org.au> -- Email: Herbert Xu [off-list ref] Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt