Red Hat Bugzilla – Bug 1021386
shmall defined incorrectly
Last modified: 2014-09-07 20:17:59 EDT
Description of problem:
Performance Tuning Guide (https://access.redhat.com/site/documentation/en-US/Red_Hat_Enterprise_Linux/6/html-single/Performance_Tuning_Guide/index.html) states the following about kernel parameter shmall
Defines the total amount of shared memory in bytes that can be used on the system at one time. The default value for machines with 64-bit architecture is 4294967296; for 32-bit architecture the default value is 268435456.
The correct unit is pages, as stated in /usr/share/doc/kernel-doc-2.6.32/Documentation/vm/hugetlbpage.txt
Version-Release number of selected component (if applicable):
Steps to Reproduce:
Unfortunately this could not be corrected in time for RHEL 6.5 GA; it will be corrected in RHEL 6.6. Thankyou for pointing out this error!
Linda, can someone from your group confirm that shmall (and presumably shmmax) values are measured in pages, not bytes?
Removing the 6.6 flag, as this update can be made asynchronously.
Docs have been corrected; shmall is now noted in pages. shmmax is still noted as measured in bytes, but I believe this is correct.
Linda, can someone from your group confirm please?
The corrected document went live over the weekend; the updated content is visible here: https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Performance_Tuning_Guide/s-memory-captun.html
Thanks again for reporting this, Robert! Any further problems, just let me know.