> On March 3, 2014, 8:51 p.m., Martin Gräßlin wrote:
> > recommendation: look at kwin/main.cpp kdemain()
Thanks.
Copy and pasted for lazy:
#ifdef M_TRIM_THRESHOLD
// Prevent fragmentation of the heap by malloc (glibc).
//
// The default threshold is 128*1024, which can result in a large memory
usage
// due to fragmentation especially if we use the raster graphicssystem. On
the
// otherside if the threshold is too low, free() starts to permanently ask
the kernel
// about shrinking the heap.
#ifdef HAVE_UNISTD_H
const int pagesize = sysconf(_SC_PAGESIZE);
#else
const int pagesize = 4*1024;
#endif // HAVE_UNISTD_H
mallopt(M_TRIM_THRESHOLD, 5*pagesize);
#endif // M_TRIM_THRESHOLD
>From what I understand there are two schools of thought:
1) set the options to cleanup more aggressively
2) whenever we delete a load of stuff we say "hey, we're probably super
fragmented now. Can you tidy up my memory please."
For a Plasma use-case, I think 2 maybe work better as we can know when we close
an applet or dialog.
- David
-----------------------------------------------------------
This is an automatically generated e-mail. To reply, visit:
https://git.reviewboard.kde.org/r/116577/#review51820
-----------------------------------------------------------
On March 3, 2014, 7:52 p.m., David Edmundson wrote:
>
> -----------------------------------------------------------
> This is an automatically generated e-mail. To reply, visit:
> https://git.reviewboard.kde.org/r/116577/
> -----------------------------------------------------------
>
> (Updated March 3, 2014, 7:52 p.m.)
>
>
> Review request for Plasma.
>
>
> Repository: plasma-framework
>
>
> Description
> -------
>
> Call malloc_trim() when deleting a dialog
>
> A dialog will typically contain lots and lots of tiny objects.
>
> Tiny mallocs are not returned to the system immediately and are left for
> us to re-use.
>
> When we delete a dialog it would be a good time to release these.
>
> This fixes the memory growth when repeatedly opening and closing the
> widget explorer.
>
> TBH: I don't /fully/ understand malloc_trim, but it does seem this patch
> makes a difference.
>
> Also I think maybe this would be better being in the destructor of
> KDeclatarive::QMLObject as well?
> or maybe we should tune the malloc options so it behaves better in general.
>
>
> Diffs
> -----
>
> src/declarativeimports/core/dialog.cpp 61e8d93
>
> Diff: https://git.reviewboard.kde.org/r/116577/diff/
>
>
> Testing
> -------
>
> The following test (courtesy of Martin K) http://paste.kde.org/pjreffopt
> creates 10 dialogs, waits 5 seconds and deletes them.
>
> Before: Memory usage in ksysguard goes up to 125Mb and stays there
> indefinitely.
> After:Memory usage in ksysguard goes up to 125Mb and when the dialogs are
> removed goes back down to 35Mb
>
>
> Thanks,
>
> David Edmundson
>
>
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