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From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Akira Iguchi <akira2.iguchi@toshiba.co.jp>
Cc: linuxppc-dev@ozlabs.org, paulus@samba.org, arnd@arndb.de
Subject: Re: [PATCH] Celleb: improve htab lock
Date: Fri, 09 Feb 2007 17:52:00 +1100	[thread overview]
Message-ID: <1171003920.2620.427.camel@localhost.localdomain> (raw)
In-Reply-To: <200702090643.l196hHDv006227@toshiba.co.jp>


> We need to turn IRQs off when calling htab functions if and only
> if it is non-atomic, so the "pSeries with LPAR" htab function have
> no spin_lock or local_irq_save/restore. We think tweaking EE bit
> locally gives a way to decrease times to be IRQs off and on again
> (yes, it's smallthing to compare with calling HV),
> so we prefer current implementation.

Well, it might be indeed worth keeping it that way to avoid long
latencies with EE off with a big batch... I'll keep it that way for now,
though I suppose I should add some documentation on the expected caller
context in machdep.h next to the function pointers.

Ben.

       reply	other threads:[~2007-02-09  6:52 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <200702090643.l196hHDv006227@toshiba.co.jp>
2007-02-09  6:52 ` Benjamin Herrenschmidt [this message]
2007-02-09  7:53 [PATCH] Celleb: improve htab lock Akira Iguchi
2007-02-09  9:19 ` Arnd Bergmann
  -- strict thread matches above, loose matches on Subject: below --
2007-02-08  6:18 Ishizaki Kou
2007-02-08  6:51 ` Arnd Bergmann
2007-02-08 20:28   ` Christoph Hellwig
2007-02-08 20:43     ` Arnd Bergmann
2007-02-08 22:32       ` Benjamin Herrenschmidt
2007-02-09  6:44         ` Akira Iguchi
2007-02-08 22:30     ` Benjamin Herrenschmidt
2007-02-08 21:20   ` Benjamin Herrenschmidt

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