Note: This bug is displayed in read-only format because
the product is no longer active in Red Hat Bugzilla.
RHEL Engineering is moving the tracking of its product development work on RHEL 6 through RHEL 9 to Red Hat Jira (issues.redhat.com). If you're a Red Hat customer, please continue to file support cases via the Red Hat customer portal. If you're not, please head to the "RHEL project" in Red Hat Jira and file new tickets here. Individual Bugzilla bugs in the statuses "NEW", "ASSIGNED", and "POST" are being migrated throughout September 2023. Bugs of Red Hat partners with an assigned Engineering Partner Manager (EPM) are migrated in late September as per pre-agreed dates. Bugs against components "kernel", "kernel-rt", and "kpatch" are only migrated if still in "NEW" or "ASSIGNED". If you cannot log in to RH Jira, please consult article #7032570. That failing, please send an e-mail to the RH Jira admins at rh-issues@redhat.com to troubleshoot your issue as a user management inquiry. The email creates a ServiceNow ticket with Red Hat. Individual Bugzilla bugs that are migrated will be moved to status "CLOSED", resolution "MIGRATED", and set with "MigratedToJIRA" in "Keywords". The link to the successor Jira issue will be found under "Links", have a little "two-footprint" icon next to it, and direct you to the "RHEL project" in Red Hat Jira (issue links are of type "https://issues.redhat.com/browse/RHEL-XXXX", where "X" is a digit). This same link will be available in a blue banner at the top of the page informing you that that bug has been migrated.
Thanks for the detailed analysis Charles. Yes, the values are off by a factor 1024 as a result of an assumption in proc_meminfo.c::refresh_proc_meminfo around line 115 which is assuming all values here need to be converted from kbytes to bytes (not so for the hugepages metrics).
I'll work on a fix today, get it resolved upstream and then propose it for 7.8.
commit 29092aa58df23fcc43f813d54b16a733d19f770c
Author: Nathan Scott <nathans>
Date: Tue Jul 16 12:28:26 2019 +1000
pmdalinux: fix hugepage metric value calculations
The values for some of the Linux kernel hugepage metrics were
being incorrectly multiplied by 1024. This was due to a code
assumption in proc_meminfo.c::refresh_proc_meminfo around line
115, which was assuming all meminfo values needed conversion
from kbytes to bytes - not so for these metrics.
The fix involves removing this assumption (for all values from
/proc/meminfo) and individually applying unit conversion where
needed only. Updated calculations are now reflected in qa/821.
Resolves Red Hat BZ #1730107.
Comment 4Charles Haithcock
2019-07-16 15:36:45 UTC
(In reply to Nathan Scott from comment #2)
> Thanks for the detailed analysis Charles.
...
> I'll work on a fix today, get it resolved upstream and then propose it for
> 7.8.
You are so welcome, and thank you for the quick turnaround on this!
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.
For information on the advisory (Low: pcp security, bug fix, and enhancement update), and where to find the updated
files, follow the link below.
If the solution does not work for you, open a new bug report.
https://access.redhat.com/errata/RHSA-2020:3869
Description of problem: pmrep is showing incorrect values for hugepages. From a customer's sosreport and pcp data: $ grep HugePages_Total sosreport-<HOSTNAME>-02415112-2019-07-11-nflredr/proc/meminfo HugePages_Total: 49152 $ pmrep mem.util.{hugepagesTotal,hugepagesFree,hugepagesRsvd,hugepagesSurp,hugepagesTotalBytes} mem.vmstat.nr_shmem_hugepages -a pcp/pmlogger/<HOSTNAME>/20190710.0.xz | head m.u.hugepagesTotal m.u.hugepagesFree m.u.hugepagesRsvd m.u.hugepagesSurp m.u.hugepagesTotalBytes m.v.nr_shmem_hugepages count count count count byte count N/A N/A N/A N/A N/A N/A 50331648 26900480 26900480 0 105553116266496 N/A 50331648 26900480 26900480 0 105553116266496 N/A 50331648 26900480 26900480 0 105553116266496 N/A From my own system: r7 # grep ^Huge /proc/meminfo HugePages_Total: 250 HugePages_Free: 250 HugePages_Rsvd: 0 HugePages_Surp: 0 Hugepagesize: 2048 kB r7 # pmrep mem.util.{hugepagesTotal,hugepagesFree,hugepagesRsvd,hugepagesSurp,hugepagesTotalBytes} mem.vmstat.nr_shmem_hugepages m.u.hugepagesTotal m.u.hugepagesFree m.u.hugepagesRsvd m.u.hugepagesSurp m.u.hugepagesTotalBytes m.v.nr_shmem_hugepages count count count count byte count 256000 256000 0 0 536870912000 N/A 256000 256000 0 0 536870912000 N/A 256000 256000 0 0 536870912000 N/A 256000 256000 0 0 536870912000 N/A Version-Release number of selected component (if applicable): From customer's sosreport: $ grep pcp sosreport-e1eep2dmkldn17-02415112-2019-07-11-nflredr/installed-rpms pcp-4.1.0-5.el7_6.x86_64 Wed Jul 10 14:55:52 2019 pcp-conf-4.1.0-5.el7_6.x86_64 Wed Jul 10 14:55:38 2019 pcp-doc-4.1.0-5.el7_6.noarch Wed Jul 10 14:55:55 2019 pcp-libs-4.1.0-5.el7_6.x86_64 Wed Jul 10 14:55:38 2019 pcp-pmda-dm-4.1.0-5.el7_6.x86_64 Wed Jul 10 14:55:39 2019 pcp-pmda-nfsclient-4.1.0-5.el7_6.x86_64 Wed Jul 10 14:55:39 2019 pcp-selinux-4.1.0-5.el7_6.x86_64 Wed Jul 10 14:55:39 2019 pcp-system-tools-4.1.0-5.el7_6.x86_64 Wed Jul 10 14:55:54 2019 pcp-zeroconf-4.1.0-5.el7_6.x86_64 Wed Jul 10 14:55:55 2019 python-pcp-4.1.0-5.el7_6.x86_64 Wed Jul 10 14:55:54 2019 And my own system : r7 # rpm -q pcp pcp-4.1.0-5.el7_6.x86_64 How reproducible: 100% Steps to Reproduce: 1. Run a pmrep or pminfo -dtf command against the hugepage 2. 3. Actual results: The hugepage count seems to be 1024x larger than it is supposed to be: 50331648 / 1024 49152.00 <--- expected from customer sosreport 256000/1024 250.00 <--- expected from my system Expected results: Correct values Additional info: - This is seen in pmrep and pminfo so maybe something with the pmda? - The mem.numa.util versions seem to be correct: $ pmrep mem.numa.util.hugepagesTotal -a pcp/pmlogger/<HOSTNAME>.ffm.cms/20190710.0.xz | head m.n.u.hugepagesTotal node0 count N/A 49152 <--- expected 49152 49152 r7 # pminfo mem.numa.util.hugepagesTotal -dtf mem.numa.util.hugepagesTotal [per-node total count of hugepages] Data Type: 64-bit unsigned int InDom: 60.19 0xf000013 Semantics: instant Units: count inst [0 or "node0"] value 250 <--- expected