Topic: Approaching the limit on PV entries

After experiencing elevated traffic one day, both my database and web server hsd the following in the messages file:

Sep 21 11:22:49 dbase kernel: Approaching the limit on PV entries, consider increasing either the vm.pmap.shpgperproc or the vm.pmap.pv_entry_max sysctl.


The following was already set:
kern.ipc.shm_use_phys=1



---------

# sysctl vm.pmap
vm.pmap.pmap_collect_active: 0
vm.pmap.pmap_collect_inactive: 0
vm.pmap.pv_entry_spare: 6811
vm.pmap.pv_entry_allocs: 240355755838
vm.pmap.pv_entry_frees: 240355712585
vm.pmap.pc_chunk_tryfail: 0
vm.pmap.pc_chunk_frees: 1365293597
vm.pmap.pc_chunk_allocs: 1365293895
vm.pmap.pc_chunk_count: 298
vm.pmap.pv_entry_count: 43253
vm.pmap.shpgperproc: 200
vm.pmap.pv_entry_max: 2653183


------------------


FreeBSD 7.1-PRERELEASE #1: Mon Dec  1 14:17:24 EST 2008
    cdizz@dbasenet:/usr/obj/usr/src/sys/PRO180
Timecounter "i8254" frequency 1193182 Hz quality 0
CPU: Intel(R) Xeon(R) CPU           E5420  @ 2.50GHz (2503.74-MHz K8-class CPU)
  Origin = "GenuineIntel"  Id = 0x1067a  Stepping = 10
  Features=0xbfebfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CLFLUSH,DTS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE>
  Features2=0x40ce3bd<SSE3,RSVD2,MON,DS_CPL,VMX,EST,TM2,SSSE3,CX16,xTPR,PDCM,DCA,<b19>,<b26>>
  AMD Features=0x20100800<SYSCALL,NX,LM>
  AMD Features2=0x1<LAHF>
  Cores per package: 4
usable memory = 4282134528 (4083 MB)
avail memory  = 4126793728 (3935 MB)

Re: Approaching the limit on PV entries

Duly noted.

Re: Approaching the limit on PV entries

Has anyone seen this before or is it a confirmed issue with FreeBSD?

Should any further tuning be done ?

Re: Approaching the limit on PV entries

This may help:

http://lists.freebsd.org/pipermail/free … 41242.html

Last edited by RoddieRod (2009-09-28 20:11:55)

"An educator never says what he himself thinks, but only that which he thinks it is good for those whom he is educating to hear."
-Nietzsche

Re: Approaching the limit on PV entries

come here
http://fixunix.com/freebsd/397205-appro … ysctl.html