r0 = openat$procfs(0xffffffffffffff9c, &(0x7f0000000000)='/proc/cgroups\x00', 0x0, 0x0)
preadv(r0, &(0x7f0000002480)=[{&(0x7f0000000080)=""/4096, 0x1000}], 0x1, 0x1, 0x0)