On Wed, Feb 19, 2014 at 04:06:09PM +0000, Sudeep Holla wrote: > From: Sudeep Holla <sudeep.holla@xxxxxxx> > > This patch adds initial support for providing processor cache information > to userspace through sysfs interface. This is based on already existing > implementations(x86, ia64, s390 and powerpc) and hence the interface is > intended to be fully compatible. > > The main purpose of this generic support is to avoid further code > duplication to support new architectures and also to unify all the existing > different implementations. > > This implementation maintains the hierarchy of cache objects which reflects > the system's cache topology. Cache devices are instantiated as needed as > CPUs come online. The cache information is replicated per-cpu even if they are > shared. A per-cpu array of cache information maintained is used mainly for > sysfs-related book keeping. > > It also implements the shared_cpu_map attribute, which is essential for > enabling both kernel and user-space to discover the system's overall cache > topology. > > This patch also add the missing ABI documentation for the cacheinfo sysfs > interface already, which is well defined and widely used. > > Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx> > Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> > Cc: Rob Herring <robh@xxxxxxxxxx> > Cc: linux-doc@xxxxxxxxxxxxxxx > --- > Documentation/ABI/testing/sysfs-devices-system-cpu | 40 ++ > drivers/base/Makefile | 2 +- > drivers/base/cacheinfo.c | 484 +++++++++++++++++++++ > include/linux/cacheinfo.h | 55 +++ > 4 files changed, 580 insertions(+), 1 deletion(-) > create mode 100644 drivers/base/cacheinfo.c > create mode 100644 include/linux/cacheinfo.h > > diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu > index d5a0d33..dabe03e 100644 > --- a/Documentation/ABI/testing/sysfs-devices-system-cpu > +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu > @@ -224,3 +224,43 @@ Description: Parameters for the Intel P-state driver > frequency range. > > More details can be found in Documentation/cpu-freq/intel-pstate.txt > + > +What: /sys/devices/system/cpu/cpu*/cache/index*/<set_of_attributes_mentioned_below> > +Date: February 2014 > +Contact: Linux kernel mailing list <linux-kernel@xxxxxxxxxxxxxxx> No, your name goes here, you don't get to run away from this new code :) > +Description: Parameters for the CPU cache attributes > + > + attributes: > + - writethrough: data is written to both the cache line > + and to the block in the lower-level memory > + - writeback: data is written only to the cache line and > + the modified cache line is written to main > + memory only when it is replaced > + - writeallocate: allocate a memory location to a cache line > + on a cache miss because of a write > + - readallocate: allocate a memory location to a cache line > + on a cache miss because of a read > + > + coherency_line_size: the minimum amount of data that gets transferred > + > + level: the cache hierarcy in the multi-level cache configuration > + > + number_of_sets: total number of sets in the cache, a set is a > + collection of cache lines with the same cache index > + > + physical_line_partition: number of physical cache line per cache tag > + > + shared_cpu_list: the list of cpus sharing the cache > + > + shared_cpu_map: logical cpu mask containing the list of cpus sharing > + the cache > + > + size: the total cache size in kB > + > + type: > + - instruction: cache that only holds instructions > + - data: cache that only caches data > + - unified: cache that holds both data and instructions > + > + ways_of_associativity: degree of freedom in placing a particular block > + of memory in the cache With this patch, does this all work for x86, or does it need more glue logic? thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
