On Thu, 2 Jul 2009 23:55:27 -0700 Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > On Thu, 2 Jul 2009 21:16:15 -0700 Paul Menage <menage@xxxxxxxxxx> wrote: > > > On Thu, Jul 2, 2009 at 7:08 PM, Andrew Morton<akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > > > > > > Why are we doing all this anyway? __To avoid presenting duplicated pids > > > to userspace? __Nothing else? > > > > To present the pids or tgids in sorted order. Removing duplicates is > > only for the case of the "procs" file; that could certainly be left to > > userspace, but it wouldn't by itself remove the existing requirement > > for a contiguous array. > > > > The seq_file iterator for these files relies on them being sorted so > > that it can pick up where it left off even in the event of the pid set > > changing between reads - it does a binary search to find the first pid > > greater than the last one that was returned, so as to guarantee that > > we return every pid that was in the cgroup before the scan started and > > remained in the cgroup until after the scan finished; there are no > > guarantees about pids that enter/leave the cgroup during the scan. > > OIC. Gee we made it hard for ourselves. That tears it. > At using "file" interface, it's not necessary to guarantee atomic-and-correct result about list of pids. It's impossible. readdir(/proc) does best-effort-jobs based on pids. plz do in such a way. It uses find_ge_pid() to scanning all exisiting pids. > > > > > > btw, did pidlist_uniq() actually needs to allocate new memory for the > > > output array? __Could it have done the filtering in-place? > > > > Yes - or just omit duplicates in the seq_file iterator, I guess > > OK. > > > So now what? lib/dynarray.c? We never need array for user interface, IIUC. Thanks, -Kame _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers
