Help regarding kernel parameter change

[raiden]

Hi

I have received a change from customer to change following kernel parameters

maxdsiz 0xF9000000
maxssiz 0x04D00000
maxdsiz_64bit 0x0000039999999999
maxssiz_64bit 0x04D00000

At this moment the above kernl parameteres have following values ( from kctune command)

maxdsiz 1073741824
maxdsiz_64bit 4294967296
maxssiz 8388608
maxssiz_64bit 268435456

The current value seems to be in decimal but the values given by customer are in hexadecimal. Now if I convert the hexadecimal values to decimal. i get a very huge number which doesnt seem to be correct.

Can some one let me know if the conversion I am doing is correct or is it some thing i am doing wrong.

[Pete Randall]

I believe SAM will do the conversion for you, showing either decimal or hex at your request.


Pete

[Don Morris_1]

kctune should take the request in hex as well as decimal. Though I don't know what they're going for with that maxdsiz_64bit value.... you really should do 0x3999999a000 since non-page aligned [assuming the usual 4kb page size here] values of the tunable are really rounded down in the kernel (which keeps track of these things internally in page units, not bytes).

[Dennis Handly]

>I have received a change from customer to maxdsiz_64bit 0x0000039999999999
>Now if I convert the hexadecimal values to decimal. i get a very huge number

Yes, the maxdsiz_64bit seems bogus:
(gdb) p 0x0000039999999999 $3 = 3958241859993
(gdb) p 0x0000039999999999 / (1024 * 1024 * 1024)
$7 = 3686

That's about 3 Tb! Do you have that much swap space?

[Don Morris_1]

It doesn't phase me... some folks just love spinning the knob all the way over -- they're really trying for "effectively unlimited" in most of these cases. Fortunately for maxdsiz{_64bit} there aren't really side effects (unlike maxssiz).

[Rita C Workman]

Sounds like yep. If you convert these from hex to decimal the numbers get very large.
maxdsiz goes to 4177526784
maxssiz goes to 80740352

...(if I entered the right number of zeroes..)

Only question to ask is "...is the customer always right ?"

Rgrds,
Rita