search for: write_point

On Tue, Dec 05, 2017 at 11:24:49PM +0200, Michael S. Tsirkin wrote: > READ_ONCE is really all over the place (some code literally replaced all > memory accesses with READ/WRITE ONCE). Yeah, so? Complain to the compiler people for forcing us into that. > Would an API like WRITE_POINTER()/smp_store_pointer make sense, > and READ_POINTER for symmetry? No, the whole point of the exercise was to get away from the fact that dependent loads are special.

On Tue, Dec 05, 2017 at 11:24:49PM +0200, Michael S. Tsirkin wrote: > READ_ONCE is really all over the place (some code literally replaced all > memory accesses with READ/WRITE ONCE). Yeah, so? Complain to the compiler people for forcing us into that. > Would an API like WRITE_POINTER()/smp_store_pointer make sense, > and READ_POINTER for symmetry? No, the whole point of the exercise was to get away from the fact that dependent loads are special.

On Tue, Dec 05, 2017 at 09:51:48PM +0200, Michael S. Tsirkin wrote: > On Tue, Dec 05, 2017 at 11:33:39AM -0800, Paul E. McKenney wrote: > > On Tue, Dec 05, 2017 at 09:24:21PM +0200, Michael S. Tsirkin wrote: [ . . . ] > > > and this barrier is no longer paired with anything until > > > you realize there's a dependency barrier within READ_ONCE. > > > >

On Tue, Dec 05, 2017 at 09:51:48PM +0200, Michael S. Tsirkin wrote: > On Tue, Dec 05, 2017 at 11:33:39AM -0800, Paul E. McKenney wrote: > > On Tue, Dec 05, 2017 at 09:24:21PM +0200, Michael S. Tsirkin wrote: [ . . . ] > > > and this barrier is no longer paired with anything until > > > you realize there's a dependency barrier within READ_ONCE. > > > >

...ore_release() to be paired with > > the new improved READ_ONCE()? > > READ_ONCE is really all over the place (some code literally replaced all > memory accesses with READ/WRITE ONCE). > > And I also prefer smp_wmb as it seems to be cheaper on ARM. > > Would an API like WRITE_POINTER()/smp_store_pointer make sense, > and READ_POINTER for symmetry? What we do in some code is to comment the pairings, allowing the other side of the pairing to be easily located. Would that work for you? Thanx, Paul

...ore_release() to be paired with > > the new improved READ_ONCE()? > > READ_ONCE is really all over the place (some code literally replaced all > memory accesses with READ/WRITE ONCE). > > And I also prefer smp_wmb as it seems to be cheaper on ARM. > > Would an API like WRITE_POINTER()/smp_store_pointer make sense, > and READ_POINTER for symmetry? What we do in some code is to comment the pairings, allowing the other side of the pairing to be easily located. Would that work for you? Thanx, Paul

...the smp_store_release() to be paired with > the new improved READ_ONCE()? > > Thanx, Paul READ_ONCE is really all over the place (some code literally replaced all memory accesses with READ/WRITE ONCE). And I also prefer smp_wmb as it seems to be cheaper on ARM. Would an API like WRITE_POINTER()/smp_store_pointer make sense, and READ_POINTER for symmetry? -- MST

...; > the new improved READ_ONCE()? > > > > READ_ONCE is really all over the place (some code literally replaced all > > memory accesses with READ/WRITE ONCE). > > > > And I also prefer smp_wmb as it seems to be cheaper on ARM. > > > > Would an API like WRITE_POINTER()/smp_store_pointer make sense, > > and READ_POINTER for symmetry? > > What we do in some code is to comment the pairings, allowing the other > side of the pairing to be easily located. Would that work for you? > > Thanx, Paul Yes, that's exactly what I did for...

...estion I will document the pairing *this read once has a barrier that is paired with that barrier*. > Complain to the compiler people for forcing us into that. In some cases when you end up with all accesses going through read/write once volatile just might better. > > Would an API like WRITE_POINTER()/smp_store_pointer make sense, > > and READ_POINTER for symmetry? > > No, the whole point of the exercise was to get away from the fact that > dependent loads are special. It's a pity that dependent stores are still special. -- MST

...: Get rid of the tname field of var_t, simplify code. widl: Add string_of_type function, prettify code. widl: Remove redundant get_var_vt function. widl: Simplify make_safearray. widl: Remove dead code in write_msft.c. widl: Remove var_t's ptr_level field and start write_pointers. Dan Kegel (1): advapi: Improve SetEntriesInAclA stub. Detlef Riekenberg (8): localspl: Code cleanup for XcvDataPort_AddPort. winspool: Return the correct errorcode in OpenPrinter (Xcv). winspool: Avoid crash on NULL parameter (XcvOpenPort in OpenPrinter). localui...

...roblem, especially if the background is white. Damjan Jovanovic (2): ws2_32: Simplify some socket tests by adding a function that generates a pair of connected sockets. ws2_32: gethostbyname("") should work. Dan Hipschman (11): widl: Remove an unnecessary assignment in write_pointers. widl: Handle pointers fields that point to structures. widl: Improve handling of offsets in the type format string. widl: Write some structures to the type format string on the fly. widl: Replace erroneously removed current_func assignment. widl: Lay framework for...

Hi all, this is the long awaited patch series to add xen device model support in qemu; the main author is Anthony Perard. Developing this series we tried to come up with the cleanest possible solution from the qemu point of view, limiting the amount of changes to common code as much as possible. The end result still requires a couple of hooks in piix_pci but overall the impact should be very