On Mon, Nov 30, 2015 at 11:14:01AM +0100, Phil Sutter wrote: > On Mon, Nov 30, 2015 at 05:37:55PM +0800, Herbert Xu wrote: > > Phil Sutter <p...@nwl.cc> wrote: > > > The following series aims to improve lib/test_rhashtable in different > > > situations: > > > > > > Patch 1 allows the kernel to reschedule so the test does not block too > > > long on slow systems. > > > Patch 2 fixes behaviour under pressure, retrying inserts in non-permanent > > > error case (-EBUSY). > > > Patch 3 auto-adjusts the upper table size limit according to the number > > > of threads (in concurrency test). In fact, the current default is > > > already too small. > > > Patch 4 makes it possible to retry inserts even in supposedly permanent > > > error case (-ENOMEM) to expose rhashtable's remaining problem of > > > -ENOMEM being not as permanent as it is expected to be. > > > > I'm sorry but this patch series is simply bogus. > > The whole series?!
Well at least patch two and four seem clearly wrong because no rhashtable user should need to retry insertions. > Did you try with my bogus patch series applied? How many CPUs does your > test system actually have? > > > So can someone please help me reproduce this? Because just loading > > test_rhashtable isn't doing it. > > As said, maybe you need to increase the number of spawned threads > (tcount=50 or so). OK that's better. I think I see the problem. The test in rhashtable_insert_rehash is racy and if two threads both try to grow the table one of them may be tricked into doing a rehash instead. I'm working on a fix. Thanks, -- Email: Herbert Xu <herb...@gondor.apana.org.au> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
