On 11/22/18 3:52 AM, Anshuman Khandual wrote: >> >> It sounds like the subset that's being exposed is insufficient for yo >> We did that because we think doing anything but a subset in sysfs will >> just blow up sysfs: MAX_NUMNODES is as high as 1024, so if we have 4 >> attributes, that's at _least_ 1024*1024*4 files if we expose *all* >> combinations. > Each permutation need not be a separate file inside all possible NODE X > (/sys/devices/system/node/nodeX) directories. It can be a top level file > enumerating various attribute values for a given (X, Y) node pair based > on an offset something like /proc/pid/pagemap. My assumption has been that this kind of thing is too fancy for sysfs: Documentation/filesystems/sysfs.txt: > Attributes should be ASCII text files, preferably with only one value > per file. It is noted that it may not be efficient to contain only one > value per file, so it is socially acceptable to express an array of > values of the same type. > > Mixing types, expressing multiple lines of data, and doing fancy > formatting of data is heavily frowned upon. Doing these things may get > you publicly humiliated and your code rewritten without notice. /proc/pid/pagemap is binary, not one-value-per-file and relatively complicated to parse. Do you really think following something like pagemap is the right model for sysfs? BTW, I'm not saying we don't need *some* interface like you propose. We almost certainly will at some point. I just don't think it will be in sysfs.
