On 1/18/22 1:19 PM, Khalid Aziz wrote: > This is a proposal to implement a mechanism in kernel to allow > userspace processes to opt into sharing PTEs. The proposal is to add > a new system call - mshare(), which can be used by a process to > create a region (we will call it mshare'd region) which can be used > by other processes to map same pages using shared PTEs. Other > process(es), assuming they have the right permissions, can then make > the mashare() system call to map the shared pages into their address > space using the shared PTEs. One thing that went over my head here was that this allowing sharing of relatively arbitrary *EXISTING* regions. The mshared'd region might be anonymous or an plain mmap()'d file. It can even be a filesystem or device DAX mmap(). In other words, donors can (ideally) share anything. Consumers have must use msharefs to access the donated areas. Right? ( btw... thanks to willy for the correction on IRC.)
