On Wed 20-04-22 12:58:05, Kent Overstreet wrote: > On Wed, Apr 20, 2022 at 08:58:36AM +0200, Michal Hocko wrote: > > On Tue 19-04-22 16:32:01, Kent Overstreet wrote: > > > This patch: > > > - Moves lib/show_mem.c to mm/show_mem.c > > > > Sure, why not. Should be a separate patch. > > > > > - Changes show_mem() to always report on slab usage > > > - Instead of reporting on all slabs, we only report on top 10 slabs, > > > and in sorted order > > > - Also reports on shrinkers, with the new shrinkers_to_text(). > > > > Why do we need/want this? It would be also great to provide an example > > of why the new output is better (in which cases) than the existing one. > > Did you read the cover letter to the patch series? Nope, only this one made it into my inbox based on my filters. I usually try to fish out other parts of the thread but I didn't this time. Besides it is always better to have a full patch description explain not only what has been changed but why as well. > But sure, I can give you an example of the new output: Calling out the changes would be really helpful, but I guess the crux is here. > 00177 16644 pages reserved > 00177 Unreclaimable slab info: > 00177 9p-fcall-cache total: 8.25 MiB active: 8.25 MiB > 00177 kernfs_node_cache total: 2.15 MiB active: 2.15 MiB > 00177 kmalloc-64 total: 2.08 MiB active: 2.07 MiB > 00177 task_struct total: 1.95 MiB active: 1.95 MiB > 00177 kmalloc-4k total: 1.50 MiB active: 1.50 MiB > 00177 signal_cache total: 1.34 MiB active: 1.34 MiB > 00177 kmalloc-2k total: 1.16 MiB active: 1.16 MiB > 00177 bch_inode_info total: 1.02 MiB active: 922 KiB > 00177 perf_event total: 1.02 MiB active: 1.02 MiB > 00177 biovec-max total: 992 KiB active: 960 KiB > 00177 Shrinkers: > 00177 super_cache_scan: objects: 127 > 00177 super_cache_scan: objects: 106 > 00177 jbd2_journal_shrink_scan: objects: 32 > 00177 ext4_es_scan: objects: 32 > 00177 bch2_btree_cache_scan: objects: 8 > 00177 nr nodes: 24 > 00177 nr dirty: 0 > 00177 cannibalize lock: 0000000000000000 > 00177 > 00177 super_cache_scan: objects: 8 > 00177 super_cache_scan: objects: 1 How does this help to analyze this allocation failure? -- Michal Hocko SUSE Labs
