Re: MAXACTION exceeded error while using systemtap

[Hien Nguyen <hien at us dot ibm dot com>]

Badari Pulavarty wrote:

> Hi,
>
> I am trying to collect pagecache usage info using systemtap
> and I get following error, while reporting. What should I 
> do fix it ?
>
> Thanks,
> Badari
>
>
> ....
> mapping = 0xffff8100b1de8a50 nrpages = 3
> mapping = 0xffff8100b1dfaa50 nrpages = 2
> mapping = 0xffff8100b1d03260 nrpages = 1
> mapping = 0xffff8100b1d04e48 nrpages = 3
> mapping = 0xffff8100b1e0ee48 nrpages = 1
> mapping = 0xffff8100b1e12658 nrpages = 1
> mapping = 0xffff8100b1e18a50 nrpages = 2
> mapping = 0xffff8100b1e1ce48 nrpages = 1
> mapping = 0xffff8100b1e2d658 nrpages = 2
> mapping = 0xffff8100b1e34a50 nrpages = 1
> mapping = 0xffff8100b1e40a50 nrpages = 3
> mapping = 0xffff8100b1e4a658 nrpages = 1
> mapping = 0xffff8100b1e9ca50 nrpages = 1
> mapping = 0xffff8100b1d6ba50 nrpages = 3
> mapping = 0xffff8100b1eb2a50 nrpages = 3
> mapping = 0xffff8100b1db3a50 nrpages = 2
> mapping = 0xffff8100b1ec2a50 nrpages = 1
> mapping = 0xffff8100b1eeb658 nrpages = 1
> ERROR: MAXACTION exceeded near embedded-code
> at /usr/local/share/systemtap/tapset/logging.stp:9:29
>
>
>
>  
>
> ------------------------------------------------------------------------
>
> #! stap
>
> global page_cache_pages
> global pageadd, pagedel
>
> function _(n) { return string(n) } 
>
> probe kernel.function("add_to_page_cache") {
> 	page_cache_pages[$mapping] = $mapping->nrpages;
> 	pageadd++
> }
>
> probe kernel.function("__remove_from_page_cache") {
> 	page_cache_pages[$page->mapping] = $page->mapping->nrpages;
> 	pagedel++
> }
>
> function report () {
>  foreach (mapping in page_cache_pages) {
> 	print("mapping = " . hexstring(mapping) . 
> 		" nrpages = " . _(page_cache_pages[mapping]) . "\n")
>  }
>  print("Totals PageAdd = " . _(pageadd) .
> 		" PageDel = " . _(pagedel) . "\n")
>  delete page_cache_pages
> }
>
> probe end {
>  report()
> }
>  
Try to reset MAXACTION once in a while with this

function reset_maxaction () %{
       if (CONTEXT && CONTEXT->actioncount)
               CONTEXT->actioncount=0;
%}

OR try to start your script with -DMAXACTION=<somehugenumber>