On Fri, Mar 25, 2022 at 09:46:46AM +0100, Karel Zak wrote: > On Thu, Mar 24, 2022 at 09:44:38AM +0100, Miklos Szeredi wrote: > > > If so, have you benchmarked lsof using this new interface? > > > > Not yet. Looked yesterday at both lsof and procps source code, and > > both are pretty complex and not easy to plug in a new interface. But > > I've not yet given up... > > I can imagine something like getvalues(2) in lsblk (based on /sys) or > in lsfd (based on /proc; lsof replacement). The tools have defined set > of information to read from kernel, so gather all the requests to the > one syscall for each process or block device makes sense and it will > dramatically reduce number of open+read+close syscalls. And do those open+read+close syscalls actually show up in measurements? Again, I tried to find a real-world application that turning those 3 into 1 would matter, and I couldn't. procps had no decreased system load that I could notice. I'll mess with lsof but that's really just a stress-test, not anything that is run all the time, right? And as others have said, using io_uring() would also solve the 3 syscall issue, but no one seems to want to convert these tools to use that, which implies that it's not really an issue for anyone :) thanks, greg k-h
