| From foo@baz Sun Jun 17 12:07:33 CEST 2018 |
| From: Alexey Dobriyan <adobriyan@gmail.com> |
| Date: Fri, 20 Apr 2018 14:56:06 -0700 |
| Subject: proc: fix /proc/loadavg regression |
| |
| From: Alexey Dobriyan <adobriyan@gmail.com> |
| |
| [ Upstream commit 9a1015b32faa7cebfe19663c886b0cfe90be1d49 ] |
| |
| Commit 95846ecf9dac ("pid: replace pid bitmap implementation with IDR |
| API") changed last field of /proc/loadavg (last pid allocated) to be off |
| by one: |
| |
| # unshare -p -f --mount-proc cat /proc/loadavg |
| 0.00 0.00 0.00 1/60 2 <=== |
| |
| It should be 1 after first fork into pid namespace. |
| |
| This is formally a regression but given how useless this field is I |
| don't think anyone is affected. |
| |
| Bug was found by /proc testsuite! |
| |
| Link: http://lkml.kernel.org/r/20180413175408.GA27246@avx2 |
| Fixes: 95846ecf9dac508 ("pid: replace pid bitmap implementation with IDR API") |
| Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> |
| Cc: "Eric W. Biederman" <ebiederm@xmission.com> |
| Cc: Gargi Sharma <gs051095@gmail.com> |
| Cc: Oleg Nesterov <oleg@redhat.com> |
| Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
| Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
| Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| arch/powerpc/platforms/cell/spufs/sched.c | 2 +- |
| fs/proc/loadavg.c | 2 +- |
| 2 files changed, 2 insertions(+), 2 deletions(-) |
| |
| --- a/arch/powerpc/platforms/cell/spufs/sched.c |
| +++ b/arch/powerpc/platforms/cell/spufs/sched.c |
| @@ -1093,7 +1093,7 @@ static int show_spu_loadavg(struct seq_f |
| LOAD_INT(c), LOAD_FRAC(c), |
| count_active_contexts(), |
| atomic_read(&nr_spu_contexts), |
| - idr_get_cursor(&task_active_pid_ns(current)->idr)); |
| + idr_get_cursor(&task_active_pid_ns(current)->idr) - 1); |
| return 0; |
| } |
| |
| --- a/fs/proc/loadavg.c |
| +++ b/fs/proc/loadavg.c |
| @@ -24,7 +24,7 @@ static int loadavg_proc_show(struct seq_ |
| LOAD_INT(avnrun[1]), LOAD_FRAC(avnrun[1]), |
| LOAD_INT(avnrun[2]), LOAD_FRAC(avnrun[2]), |
| nr_running(), nr_threads, |
| - idr_get_cursor(&task_active_pid_ns(current)->idr)); |
| + idr_get_cursor(&task_active_pid_ns(current)->idr) - 1); |
| return 0; |
| } |
| |