From: Holger.VanKoll@SWISSCOM.COM
Date: Thu May 15 2003 - 08:06:28 EDT
Well,
I think a "pinned page" is a page that has to be kept in ram.
As long as its part of a working segment, thats equal to "not page out"
or "not swap out" (both terms are used within aix-docu).
So, the point of pinning persistent segments might be to allow fast
execution without loading pages from storage.
Those two processes where I noticed pinned persistent pages (hatsd and
shdaemon) are both time-critical.
This is all guessing, but sounds reasonable to me.
Anyway, if someone knows for sure, please post.
Regards,
Holger
> -----Original Message-----
> From: Van Koll Holger, IT-DCS-SES-UN
> Sent: Thursday, May 15, 2003 12:06 PM
> To: aix-l@Princeton.EDU
> Subject: pinning persistent storage
>
> Hello,
>
> pinned memory is memory that is marked as "do not page out", correct?
>
> persistent storage will never be paged out, correct?
>
> If both is correct, why are there some pinned pages of persistent
> segments?
>
> root@0-tvgicsc1 179# svmon -G
> work pers clnt
> pin 6740 172 0
> root@0-tvgicsc1 180# svmon -S -f|grep -v "0 - -"
> Vsid Esid Type Description Inuse Pin Pgsp Virtual
> Addr Range
> 78dc - pers /dev/hd2:84132 181 172 - -
> 0..714
> root@0-tvgicsc1 181# ncheck -i 84132 /dev/hd2
> /dev/hd2:
> 84132 /sbin/rsct/bin/hatsd
>
>
> or, on another system:
>
> sbe12169 # svmon -G
> work pers clnt lpage
> pin 786299 5 0 0
>
> sbe12169 # svmon -S -f|grep -v "0 - -"
> Vsid Esid Type Description LPage Inuse Pin
> Pgsp Virtual
> 4e0538 - pers /dev/hd2:10817 - 5 5
> - -
> sbe12169 # ncheck -i 10817 /dev/hd2
> /dev/hd2:
> 10817 /sbin/shdaemon
>
> Regards,
>
> Holger
>
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