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the product is no longer active in Red Hat Bugzilla.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.
Description of problem:
The following perf command is broken in RHEL-9:
# perf script -F "comm,pid,cpu,event,addr,data_src,weight,ip,sym,phys_addr"
Samples for 'cpu/mem-loads,ldlat=30/P' event do not have WEIGHT attribute set. Cannot print 'weight' field.
Version-Release number of selected component (if applicable):
How reproducible:
Easy to reproduce.
Steps to Reproduce:
Just run a simple command, such as:
# perf mem record strings /boot/vmlinuz-`uname -r` > /dev/null 2>&1
# perf script -F "weight"
Actual results:
# perf mem record strings /boot/vmlinuz-`uname -r` > /dev/null 2>&1
# perf script -F "weight"
Samples for 'cpu/mem-loads,ldlat=30/P' event do not have WEIGHT attribute set. Cannot print 'weight' field.
Expected results:
# perf mem record strings /boot/vmlinuz-`uname -r` > /dev/null 2>&1
# perf script -F "weight" | head -10
118
56
819
51
238
57
281
326
417
148
Additional info:
This feature is important to us. When triaging performance problems, it is very common to try and understand what load instructions are taking the longest and why. Here's a snipit for how we use it. The weight field shows the machine cycles needed for each load (sample).
perf.jirka.v2 script -F "comm,pid,cpu,addr,weight,ip,sym" |sort -nrk5 | head -10
tugtest 77011 [004] 406100 2944 401868 acquire_lock
tugtest 77011 [006] 406100 2868 401868 acquire_lock
tugtest 77011 [006] 406100 2815 401868 acquire_lock
tugtest 77011 [006] 406100 2797 401868 acquire_lock
tugtest 77011 [004] 406100 2756 401868 acquire_lock
tugtest 77011 [004] 406100 2741 401868 acquire_lock
tugtest 77011 [004] 406100 2604 401868 acquire_lock
tugtest 77011 [004] 406100 2582 401868 acquire_lock
tugtest 77011 [006] 406100 2563 401868 acquire_lock
tugtest 77011 [006] 406100 2557 401868 acquire_lock
In the above example, the load latencies are only in the 2-3K range (not too bad). The more serious ones are often up in the 10K->60K range.
Side node: This bug has already been fixed and the patch has been submitted upstream.
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 (new packages: kernel), 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/RHBA-2022:3907
Description of problem: The following perf command is broken in RHEL-9: # perf script -F "comm,pid,cpu,event,addr,data_src,weight,ip,sym,phys_addr" Samples for 'cpu/mem-loads,ldlat=30/P' event do not have WEIGHT attribute set. Cannot print 'weight' field. Version-Release number of selected component (if applicable): How reproducible: Easy to reproduce. Steps to Reproduce: Just run a simple command, such as: # perf mem record strings /boot/vmlinuz-`uname -r` > /dev/null 2>&1 # perf script -F "weight" Actual results: # perf mem record strings /boot/vmlinuz-`uname -r` > /dev/null 2>&1 # perf script -F "weight" Samples for 'cpu/mem-loads,ldlat=30/P' event do not have WEIGHT attribute set. Cannot print 'weight' field. Expected results: # perf mem record strings /boot/vmlinuz-`uname -r` > /dev/null 2>&1 # perf script -F "weight" | head -10 118 56 819 51 238 57 281 326 417 148 Additional info: This feature is important to us. When triaging performance problems, it is very common to try and understand what load instructions are taking the longest and why. Here's a snipit for how we use it. The weight field shows the machine cycles needed for each load (sample). perf.jirka.v2 script -F "comm,pid,cpu,addr,weight,ip,sym" |sort -nrk5 | head -10 tugtest 77011 [004] 406100 2944 401868 acquire_lock tugtest 77011 [006] 406100 2868 401868 acquire_lock tugtest 77011 [006] 406100 2815 401868 acquire_lock tugtest 77011 [006] 406100 2797 401868 acquire_lock tugtest 77011 [004] 406100 2756 401868 acquire_lock tugtest 77011 [004] 406100 2741 401868 acquire_lock tugtest 77011 [004] 406100 2604 401868 acquire_lock tugtest 77011 [004] 406100 2582 401868 acquire_lock tugtest 77011 [006] 406100 2563 401868 acquire_lock tugtest 77011 [006] 406100 2557 401868 acquire_lock In the above example, the load latencies are only in the 2-3K range (not too bad). The more serious ones are often up in the 10K->60K range. Side node: This bug has already been fixed and the patch has been submitted upstream.