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Created attachment 477912[details]
Patch to replace list_for_each_entry with list_for_each_entry_safe in nfs_access_cache_shrinker
Description of problem:
Customer noticed kswapd was getting stuck consuming 100% cpu. Backtraces revealed the culprit to be nfs_access_cache_shrinker. Upstream includes a patch (attached) which corrects a flaw in this function where it uses the wrong list iteration macro to move over the list. It was thus possible for the loop iterator to get "lost" and end up iterating the same now-isolated node over and over forever.
Version-Release number of selected component (if applicable):
kernel 2.6.32-71.el6
Created attachment 477912 [details] Patch to replace list_for_each_entry with list_for_each_entry_safe in nfs_access_cache_shrinker Description of problem: Customer noticed kswapd was getting stuck consuming 100% cpu. Backtraces revealed the culprit to be nfs_access_cache_shrinker. Upstream includes a patch (attached) which corrects a flaw in this function where it uses the wrong list iteration macro to move over the list. It was thus possible for the loop iterator to get "lost" and end up iterating the same now-isolated node over and over forever. Version-Release number of selected component (if applicable): kernel 2.6.32-71.el6