Messages in this thread | | | Date | Wed, 3 Sep 2014 10:56:06 -0700 | From | Greg Kroah-Hartman <> | Subject | Re: [PATCH 21/26] tty: Convert tty_struct bitfield to bools |
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On Wed, Sep 03, 2014 at 11:10:45AM -0400, Peter Hurley wrote: > On 09/03/2014 08:19 AM, One Thousand Gnomes wrote: > >> Ahh. Thanks for the insight, Alan. > >> > >> But set_bit() et. al. will generate an incredible amount of churn; > >> what if I split the fields up to prevent false-sharing? > > > > Do you feel lucky ;-) > > Hahaha :) > > > I'd rather set_bit and friends were used. They exist largely for this > > kind of reason and they also have atomic test/set methods which may in > > the longer term be very useful. > > > > Yes it is churn can't argue with that. > > Yuck. There should be a better way. IXANY mode is suddenly going to > have a ton of unnecessary bus locks on x86.
True, but at least it will be correct, which I'm guessing today it isn't :(
> Note the ctrl_status field is a byte as well, which can't be RMW'ed by > the bit-locked primitives, and definitely should not be aggregated with > any adjacent field.
Never trust what an ia64 compiler can, and will, do...
greg k-h
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