Date: Wed, 07 Jan 2015 08:51:03 +0000 From: bugzilla-noreply@freebsd.org To: freebsd-bugs@FreeBSD.org Subject: [Bug 196586] [vm][patch] Using sysctl to set new limits on kern.ipc.nmbjumbo9 or kern.ipc.nmbjumbo16 does not work as expected Message-ID: <bug-196586-8@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=196586 Bug ID: 196586 Summary: [vm][patch] Using sysctl to set new limits on kern.ipc.nmbjumbo9 or kern.ipc.nmbjumbo16 does not work as expected Product: Base System Version: 9.3-RELEASE Hardware: Any OS: Any Status: New Severity: Affects Some People Priority: --- Component: kern Assignee: freebsd-bugs@FreeBSD.org Reporter: arnaud.ysmal@stormshield.eu Created attachment 151450 --> https://bugs.freebsd.org/bugzilla/attachment.cgi?id=151450&action=edit Use (uk_maxpages / uk_ppera) * uk_ipers to compute the number of items Overview: Using sysctl to set a new value to kern.ipc.nmbjumbo9 or kern.ipc.nmbjumbo16 leads to a wrong value. This appears in FreeBSD 9.3 with the revision 254515 (https://svnweb.freebsd.org/base?view=revision&revision=254515) which MFC the revision 243631. How to reproduce: # sysctl kern.ipc.nmbjumbo9=224000 kern.ipc.nmbjumbo9: 223263 -> 672000 Expected Results: # sysctl kern.ipc.nmbjumbo9=224000 kern.ipc.nmbjumbo9: 223263 -> 224000 Audit: The sysctls functions in sys/kern/kern_mbuf.c got the new value from the uma_zone_set_max (sys/vm/uma_core.c) function. The formula used in uma_core.c to compute the number of items based on the number of pages is not always the same (uk_ppera is sometimes missing). Fix: The enclosed patch fixes this issue by always using the same formula to compute the number of items. Additional Information: This report is a follow up of my mail on freebsd-net (https://lists.freebsd.org/pipermail/freebsd-net/2014-December/040584.html). This issue was previously discussed on FreeBSD-hackers (https://lists.freebsd.org/pipermail/freebsd-hackers/2014-September/046158.html). -- You are receiving this mail because: You are the assignee for the bug.
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