Messages in this thread | | | Date | Mon, 29 Jun 2015 20:59:46 +0900 | From | Akira Nakajima <> | Subject | [QUESTION 1/2] Simple question about pagemap |
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Sorry for simple question.
1. Why physical address is greater than the installed memory?
-- Installed memory is 8GB
RHEL7# grep MemTotal /proc/meminfo MemTotal: 7840900 kB
RHEL7# dmidecode | grep -A 5 'Memory Device' | grep Size Size: 4096 MB Size: No Module Installed Size: 4096 MB Size: No Module Installed
-- Physical address is greater than 8GB
RHEL7# wc -c /proc/kpageflags 19136504 /proc/kpageflags
19136504 / 8Bytes x 4KB = 9.125GB
-- My program which is using pagemap shows following. ( From left, Phy_addr, Phy_addr(hex), Virtual_addr(hex), process(PID), kpageflags, [kpagecount] )
9 G 127 M 112 K 247f1c000 v_addr: 7f8bf44b7000 NetworkManager (630) __RU_lA____M_____________ [56] 9 G 127 M 116 K 247f1d000 v_addr: 7fa9b3adf000 gdm-session-wor(1964) __RU_lA____M_____________ [5] 9 G 127 M 120 K 247f1e000 v_addr: 7f177ce2e000 systemd-journal(514) __RU_lA____M_____________ [87]
-- crash shows same physical address.
crash> vtop -c 514 7f177ce2e000 VIRTUAL PHYSICAL 7f177ce2e000 247f1e000
Why greater than installed memory?
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