search for: _________p1

...enario in "DATA DEPENDENCY BARRIERS" section and > > >>fails. > > >The trick is that lockless_dereference() contains an > > >smp_read_barrier_depends(): > > > > > >#define lockless_dereference(p) \ > > >({ \ > > > typeof(p) _________p1 = READ_ONCE(p); \ > > > smp_read_barrier_depends(); /* Dependency order vs. p above. */ \ > > > (_________p1); \ > > >}) > > > > > >Or am I missing your point? > > > > WRC+addr+addr has no any barrier. lockless_dereference() has a > >...

...enario in "DATA DEPENDENCY BARRIERS" section and > > >>fails. > > >The trick is that lockless_dereference() contains an > > >smp_read_barrier_depends(): > > > > > >#define lockless_dereference(p) \ > > >({ \ > > > typeof(p) _________p1 = READ_ONCE(p); \ > > > smp_read_barrier_depends(); /* Dependency order vs. p above. */ \ > > > (_________p1); \ > > >}) > > > > > >Or am I missing your point? > > > > WRC+addr+addr has no any barrier. lockless_dereference() has a > >...

...ily changed to different scenario which >> fits some of scenario in "DATA DEPENDENCY BARRIERS" section and >> fails. > The trick is that lockless_dereference() contains an > smp_read_barrier_depends(): > > #define lockless_dereference(p) \ > ({ \ > typeof(p) _________p1 = READ_ONCE(p); \ > smp_read_barrier_depends(); /* Dependency order vs. p above. */ \ > (_________p1); \ > }) > > Or am I missing your point? WRC+addr+addr has no any barrier. lockless_dereference() has a barrier. I don't see a common points between this and that in your answ...

...ily changed to different scenario which >> fits some of scenario in "DATA DEPENDENCY BARRIERS" section and >> fails. > The trick is that lockless_dereference() contains an > smp_read_barrier_depends(): > > #define lockless_dereference(p) \ > ({ \ > typeof(p) _________p1 = READ_ONCE(p); \ > smp_read_barrier_depends(); /* Dependency order vs. p above. */ \ > (_________p1); \ > }) > > Or am I missing your point? WRC+addr+addr has no any barrier. lockless_dereference() has a barrier. I don't see a common points between this and that in your answ...

I need some time to understand your test examples. However, On 01/14/2016 12:34 PM, Paul E. McKenney wrote: > > > The WRC+addr+addr is OK because data dependencies are not required to be > transitive, in other words, they are not required to flow from one CPU to > another without the help of an explicit memory barrier. I don't see any reliable way to fit WRC+addr+addr into

I need some time to understand your test examples. However, On 01/14/2016 12:34 PM, Paul E. McKenney wrote: > > > The WRC+addr+addr is OK because data dependencies are not required to be > transitive, in other words, they are not required to flow from one CPU to > another without the help of an explicit memory barrier. I don't see any reliable way to fit WRC+addr+addr into

...then > after years it can be easily changed to different scenario which > fits some of scenario in "DATA DEPENDENCY BARRIERS" section and > fails. The trick is that lockless_dereference() contains an smp_read_barrier_depends(): #define lockless_dereference(p) \ ({ \ typeof(p) _________p1 = READ_ONCE(p); \ smp_read_barrier_depends(); /* Dependency order vs. p above. */ \ (_________p1); \ }) Or am I missing your point? > > Transitivity is > > Peter Zijlstra recently wrote: "In particular we're very much all > 'confused' about the various notions...

...which > >>fits some of scenario in "DATA DEPENDENCY BARRIERS" section and > >>fails. > >The trick is that lockless_dereference() contains an > >smp_read_barrier_depends(): > > > >#define lockless_dereference(p) \ > >({ \ > > typeof(p) _________p1 = READ_ONCE(p); \ > > smp_read_barrier_depends(); /* Dependency order vs. p above. */ \ > > (_________p1); \ > >}) > > > >Or am I missing your point? > > WRC+addr+addr has no any barrier. lockless_dereference() has a > barrier. I don't see a common points...

...RIERS" section and > > > >>fails. > > > >The trick is that lockless_dereference() contains an > > > >smp_read_barrier_depends(): > > > > > > > >#define lockless_dereference(p) \ > > > >({ \ > > > > typeof(p) _________p1 = READ_ONCE(p); \ > > > > smp_read_barrier_depends(); /* Dependency order vs. p above. */ \ > > > > (_________p1); \ > > > >}) > > > > > > > >Or am I missing your point? > > > > > > WRC+addr+addr has no any barrier. lock...

...gt; > >>fails. > > > > >The trick is that lockless_dereference() contains an > > > > >smp_read_barrier_depends(): > > > > > > > > > >#define lockless_dereference(p) \ > > > > >({ \ > > > > > typeof(p) _________p1 = READ_ONCE(p); \ > > > > > smp_read_barrier_depends(); /* Dependency order vs. p above. */ \ > > > > > (_________p1); \ > > > > >}) > > > > > > > > > >Or am I missing your point? > > > > > > > > WRC...

...gt; > >>fails. > > > > >The trick is that lockless_dereference() contains an > > > > >smp_read_barrier_depends(): > > > > > > > > > >#define lockless_dereference(p) \ > > > > >({ \ > > > > > typeof(p) _________p1 = READ_ONCE(p); \ > > > > > smp_read_barrier_depends(); /* Dependency order vs. p above. */ \ > > > > > (_________p1); \ > > > > >}) > > > > > > > > > >Or am I missing your point? > > > > > > > > WRC...