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From: NeilBrown <neilb@suse.com>
To: Thomas Graf <tgraf@suug.ch>,
	Herbert Xu <herbert@gondor.apana.org.au>,
	David Miller <davem@davemloft.net>
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	Guenter Roeck <linux@roeck-us.net>
Subject: [PATCH 0/5] Fix rhashtable bit-locking for m68k
Date: Fri, 12 Apr 2019 11:52:07 +1000	[thread overview]
Message-ID: <155503371949.17793.8266195008003399968.stgit@noble.brown> (raw)

As reported by Guenter Roeck, the new rhashtable bit-locking
doesn't work on m68k as it only requires 2-byte alignment, so BIT(1)
is addresses is not unused.

We current use BIT(0) to identify a NULLS marker, but that is only
needed in ->next pointers.  The bucket head does not need a NULLS
marker, so the lsb there can be used for locking.

the first 4 patches make some small improvements and re-arrange some
code.  The final patch converts to using only BIT(0) for these two
different special purposes.

I had previously suggested dropping the series until I fix it.  Given
that this was fairly easy, I retract that I think it best simply to
add these patches to fix the code.

Thanks,
NeilBrown

---

NeilBrown (5):
      rhashtable: fix some __rcu annotation errors
      rhashtable: reorder some inline functions and macros.
      rhashtable: move dereference inside rht_ptr()
      rhashtable: replace rht_ptr_locked() with rht_assign_locked()
      rhashtable: use BIT(0) for locking.


 include/linux/rhashtable.h |  226 +++++++++++++++++++++++++-------------------
 lib/rhashtable.c           |   24 ++---
 lib/test_rhashtable.c      |    2 
 3 files changed, 142 insertions(+), 110 deletions(-)

--
Signature


             reply	other threads:[~2019-04-12  1:52 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-04-12  1:52 NeilBrown [this message]
2019-04-12  1:52 ` [PATCH 1/5] rhashtable: fix some __rcu annotation errors NeilBrown
2019-04-12  1:52 ` [PATCH 5/5] rhashtable: use BIT(0) for locking NeilBrown
2019-04-12  1:52 ` [PATCH 2/5] rhashtable: reorder some inline functions and macros NeilBrown
2019-05-14 19:25   ` Jakub Kicinski
2019-04-12  1:52 ` [PATCH 4/5] rhashtable: replace rht_ptr_locked() with rht_assign_locked() NeilBrown
2019-04-12  1:52 ` [PATCH 3/5] rhashtable: move dereference inside rht_ptr() NeilBrown
2019-04-12 18:08 ` [PATCH 0/5] Fix rhashtable bit-locking for m68k Guenter Roeck
2019-04-13  0:34   ` David Miller

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