Messages in this thread |  | | | Date | Fri, 02 Sep 2011 12:32:25 -0700 | | From | Jeremy Fitzhardinge <> | | Subject | Re: [PATCH 06/13] x86/ticketlock: add slowpath logic |
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On 09/02/2011 11:46 AM, Eric Northup wrote: > On Thu, Sep 1, 2011 at 5:54 PM, Jeremy Fitzhardinge <jeremy@goop.org> wrote: >> From: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> >> >> Maintain a flag in both LSBs of the ticket lock which indicates whether >> anyone is in the lock slowpath and may need kicking when the current >> holder unlocks. The flags are set when the first locker enters >> the slowpath, and cleared when unlocking to an empty queue. > Are there actually two flags maintained? I only see the one in the > ticket tail getting set/cleared/tested.
Yeah, there's only one flag, so there's a spare bit in the other half.
j
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