Le 14/02/2019 à 18:10, Keith Busch a écrit : > System memory may have caches to help improve access speed to frequently > requested address ranges. While the system provided cache is transparent > to the software accessing these memory ranges, applications can optimize > their own access based on cache attributes. > > Provide a new API for the kernel to register these memory-side caches > under the memory node that provides it. > > The new sysfs representation is modeled from the existing cpu cacheinfo > attributes, as seen from /sys/devices/system/cpu/<cpu>/cache/. Unlike CPU > cacheinfo though, the node cache level is reported from the view of the > memory. A higher level number is nearer to the CPU, while lower levels > are closer to the last level memory. > > The exported attributes are the cache size, the line size, associativity, > and write back policy, and add the attributes for the system memory > caches to sysfs stable documentation. > > Signed-off-by: Keith Busch <keith.busch@xxxxxxxxx> > --- > Documentation/ABI/stable/sysfs-devices-node | 35 +++++++ > drivers/base/node.c | 151 ++++++++++++++++++++++++++++ > include/linux/node.h | 34 +++++++ > 3 files changed, 220 insertions(+) > > diff --git a/Documentation/ABI/stable/sysfs-devices-node b/Documentation/ABI/stable/sysfs-devices-node > index cd64b62152ba..5c88cb9ca14e 100644 > --- a/Documentation/ABI/stable/sysfs-devices-node > +++ b/Documentation/ABI/stable/sysfs-devices-node > @@ -143,3 +143,38 @@ Contact: Keith Busch <keith.busch@xxxxxxxxx> > Description: > This node's write latency in nanoseconds when access > from nodes found in this class's linked initiators. > + > +What: /sys/devices/system/node/nodeX/memory_side_cache/indexY/ > +Date: December 2018 > +Contact: Keith Busch <keith.busch@xxxxxxxxx> > +Description: > + The directory containing attributes for the memory-side cache > + level 'Y'. > + > + The caches associativity: 0 for direct mapped, non-zero if > +What: /sys/devices/system/node/nodeX/memory_side_cache/indexY/associativity > +Date: December 2018 > +Contact: Keith Busch <keith.busch@xxxxxxxxx> > +Description: > + The caches associativity: 0 for direct mapped, non-zero if > + indexed. Should we rename "associativity" into "indexing" or something else? When I see "associativity" that contains 0, I tend to interpret this as the associativity value itself, which would mean fully-associative here (as in CPU-side cache "ways_of_associativity" attribute), while actually 0 means direct-mapped (ie 1-associative) with yout semantics. Brice
