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Groups > linux.kernel > #1279747
| From | Herbert Xu <herbert@gondor.apana.org.au> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH v2 0/4] improve fault-tolerance of rhashtable runtime-test |
| Date | 2015-11-30 11:20 +0100 |
| Message-ID | <qAtIR-2gq-15@gated-at.bofh.it> (permalink) |
| References | <qwXvP-1JB-15@gated-at.bofh.it> <qAt6b-1Ny-17@gated-at.bofh.it> <qAtIR-2gq-1@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
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 <phil@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 <herbert@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 linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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[PATCH v2 0/4] improve fault-tolerance of rhashtable runtime-test Phil Sutter <phil@nwl.cc> - 2015-11-20 18:20 +0100
[PATCH v2 1/4] rhashtable-test: add cond_resched() to thread test Phil Sutter <phil@nwl.cc> - 2015-11-20 18:20 +0100
Re: [PATCH v2 0/4] improve fault-tolerance of rhashtable runtime-test David Miller <davem@davemloft.net> - 2015-11-23 18:40 +0100
Re: [PATCH v2 0/4] improve fault-tolerance of rhashtable runtime-test Herbert Xu <herbert@gondor.apana.org.au> - 2015-11-30 10:40 +0100
Re: [PATCH v2 0/4] improve fault-tolerance of rhashtable runtime-test Phil Sutter <phil@nwl.cc> - 2015-11-30 11:20 +0100
Re: [PATCH v2 0/4] improve fault-tolerance of rhashtable runtime-test Herbert Xu <herbert@gondor.apana.org.au> - 2015-11-30 11:20 +0100
rhashtable: Prevent spurious EBUSY errors on insertion Herbert Xu <herbert@gondor.apana.org.au> - 2015-12-03 13:50 +0100
Re: rhashtable: Prevent spurious EBUSY errors on insertion Phil Sutter <phil@nwl.cc> - 2015-12-03 16:40 +0100
Re: rhashtable: Prevent spurious EBUSY errors on insertion David Miller <davem@davemloft.net> - 2015-12-04 20:40 +0100
rhashtable: ENOMEM errors when hit with a flood of insertions Herbert Xu <herbert@gondor.apana.org.au> - 2015-12-03 14:00 +0100
RE: rhashtable: ENOMEM errors when hit with a flood of insertions David Laight <David.Laight@ACULAB.COM> - 2015-12-03 16:20 +0100
Re: rhashtable: ENOMEM errors when hit with a flood of insertions Eric Dumazet <eric.dumazet@gmail.com> - 2015-12-03 17:10 +0100
Re: rhashtable: ENOMEM errors when hit with a flood of insertions Herbert Xu <herbert@gondor.apana.org.au> - 2015-12-04 01:10 +0100
rhashtable: Use __vmalloc with GFP_ATOMIC for table allocation Herbert Xu <herbert@gondor.apana.org.au> - 2015-12-04 15:50 +0100
Re: rhashtable: Use __vmalloc with GFP_ATOMIC for table allocation Eric Dumazet <eric.dumazet@gmail.com> - 2015-12-04 18:50 +0100
Re: rhashtable: Use __vmalloc with GFP_ATOMIC for table allocation Phil Sutter <phil@nwl.cc> - 2015-12-04 19:20 +0100
Re: rhashtable: Use __vmalloc with GFP_ATOMIC for table allocation Herbert Xu <herbert@gondor.apana.org.au> - 2015-12-05 08:10 +0100
Re: rhashtable: Use __vmalloc with GFP_ATOMIC for table allocation Thomas Graf <tgraf@suug.ch> - 2015-12-07 16:40 +0100
Re: rhashtable: Use __vmalloc with GFP_ATOMIC for table allocation David Miller <davem@davemloft.net> - 2015-12-07 20:40 +0100
Re: rhashtable: Use __vmalloc with GFP_ATOMIC for table allocation Thomas Graf <tgraf@suug.ch> - 2015-12-09 03:20 +0100
Re: rhashtable: Use __vmalloc with GFP_ATOMIC for table allocation Herbert Xu <herbert@gondor.apana.org.au> - 2015-12-09 03:30 +0100
Re: rhashtable: Use __vmalloc with GFP_ATOMIC for table allocation Herbert Xu <herbert@gondor.apana.org.au> - 2015-12-09 03:40 +0100
Re: rhashtable: Use __vmalloc with GFP_ATOMIC for table allocation Thomas Graf <tgraf@suug.ch> - 2015-12-09 03:50 +0100
Re: rhashtable: Use __vmalloc with GFP_ATOMIC for table allocation Thomas Graf <tgraf@suug.ch> - 2015-12-09 03:40 +0100
Re: rhashtable: Use __vmalloc with GFP_ATOMIC for table allocation David Miller <davem@davemloft.net> - 2015-12-04 23:00 +0100
Re: rhashtable: Use __vmalloc with GFP_ATOMIC for table allocation Herbert Xu <herbert@gondor.apana.org.au> - 2015-12-05 08:10 +0100
Re: rhashtable: Use __vmalloc with GFP_ATOMIC for table allocation David Miller <davem@davemloft.net> - 2015-12-06 04:50 +0100
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