With this patch, we will be close to an implementation
which will be needed when accommodating tasks/threads.
The following explanation was from an earlier message:
The slabtop requirements are similar to those of PIDs.
One must accommodate the variable number of slab nodes
(PIDs) while also accepting different data (char * and
unsigned long). Furthermore, some generalized means to
sort all that acquired stuff must somehow be provided.
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So this patch expands the API to provide dynamic chain
allocation plus allow sorting of those dynamic chains.
While specific to slab needs (nodes, not global stats)
it is not too early to begin to think of newlib chains
as the opaque replacement for a deprecated old proc_t.
Better yet, any newlib chain is inherently variable in
length, something the old proc_t couldn't claim to be.
Of course, as we get to PIDs we'll want to grow/shrink
chains (easily accomplished with a special item enum).
And we'll want to grow/shrink those **head arrays too.
But these minor details don't seem insurmountable now.
Signed-off-by: Jim Warner <james.warner@comcast.net>
This was Craig's original patch, referenced below, but
it was never pushed to newlib. It has now been rebased
on top of some diskstat stuff to serve as a beginning.
The original effort was perfectly serviceable (after a
memory leak was fixed) but the approach would not have
served future PID needs when that proc_t went bye bye.
The slabtop requirements are similar to those of PIDs.
One must accommodate the variable number of slab nodes
(PIDs) while also accepting different data (char * and
unsigned long). Furthermore, some generalized means to
sort all that acquired stuff must somehow be provided.
So I wanted to try a different approach that seemed to
hold potential for satisfying future top and ps needs.
Subsequent commits will make that attempt, building on
Craig's original patch whose commit msg appears below.
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All of the /proc/slabinfo related calls have been changed
here. They follow the same procps_slabinfo_* format.
Made both the slabtop and vmstat programs use the new
API as one was using the old one and one was just sort
of trying to do its own thing.
Sorting of slabnodes is also possible via the library.
Reference(s):
http://www.freelists.org/post/procps/Sorting-slabsprocesses,3http://www.freelists.org/post/procps/library-rework-slabinfo-calls
Signed-off-by: Craig Small <csmall@enc.com.au>
Signed-off-by: Jim Warner <james.warner@comcast.net>
There soon will be slab types per cgroup meaning the name of the slab
will have the cgroup name in parathensis after the slab name. This
minor change increases the slab name size to cater for this.
Signed-off-by: Craig Small <csmall@enc.com.au>
