Bug 25978 - improve debuginfod prefetching / fdcache-management logic
Summary: improve debuginfod prefetching / fdcache-management logic
Status: RESOLVED FIXED
Alias: None
Product: elfutils
Classification: Unclassified
Component: debuginfod (show other bugs)
Version: unspecified
: P2 normal
Target Milestone: ---
Assignee: Noah Sanci
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2020-05-12 15:41 UTC by Frank Ch. Eigler
Modified: 2021-07-14 17:41 UTC (History)
3 users (show)

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Description Frank Ch. Eigler 2020-05-12 15:41:51 UTC
The debuginfod fdcache-prefetch logic has been observed to show some degeneraacies in operation.  Since fdcache evictions are done frequently, and freshly prefetched archive elements are put at the back of lru[], each eviction round can summarily nuke things that were just prefetched .... and are just going to be prefetched again.  It would be better to have two lru lists, or being able to insert newly prefetched entries somewhere in the middle of the list rather than at the very very end.
Comment 1 Mark Wielaard 2021-07-14 17:41:50 UTC
commit fddaa57358c53ab86856d9ed0089d1b4ec1b7a1e
Author: Noah <nsanci@redhat.com>
Date:   Thu Jun 10 10:29:45 2021 -0400

    debuginfod: PR25978 - Created the prefetch fdcache
    
    The debuginfod fdcache-prefetch logic has been observed to show some
    degeneracies in operation.  Since fdcache evictions are done
    frequently, and freshly prefetched archive elements are put at the
    back of lru[], each eviction round can summarily nuke things that
    were just prefetched .... and are just going to be prefetched again.
    It would be better to have two lru lists, or being able to insert
    newly prefetched entries somewhere in the middle of the list rather
    than at the very very end.
    
    https://sourceware.org/bugzilla/show_bug.cgi?id=25978
    
    Signed-off-by: Noah Sanci <nsanci@redhat.com>