On Tue, Nov 30, 2021 at 06:59:58PM +0100, Mike Galbraith wrote: > On Tue, 2021-11-30 at 17:27 +0000, Mel Gorman wrote: > > > > Obviously a fairly different experience and most likely due to the > > underlying storage. > > I bet a virtual nickle this is the sore spot. > You win a virtual nickle! Using an older laptop with slower storage and less memory a frequency analysis of the stall reasons and source showed the top triggering event was Event count: 6210 mm_vmscan_throttled: nid=0 usec_timeout=100000 usect_delayed=xxx reason=VMSCAN_THROTTLE_WRITEBACK => trace_event_raw_event_mm_vmscan_throttled <ffffffff9987224a> => reclaim_throttle <ffffffff99873df2> => shrink_node <ffffffff99875bd5> => do_try_to_free_pages <ffffffff99875cf8> => try_to_free_pages <ffffffff998772e3> => __alloc_pages_slowpath.constprop.114 <ffffffff998c2ad9> => __alloc_pages <ffffffff998c366b> => folio_alloc <ffffffff998e4107> => page_cache_ra_unbounded <ffffffff99868fab> => filemap_fault <ffffffff9985cb13> => __do_fault <ffffffff99899361> => __handle_mm_fault <ffffffff998a1470> => handle_mm_fault <ffffffff998a19ba> => do_user_addr_fault <ffffffff99688734> => exc_page_fault <ffffffff9a07bcd7> => asm_exc_page_fault <ffffffff9a200ace> -- Mel Gorman SUSE Labs