Hi yu,
On 12/2/2023 5:22 AM, Yu Zhao wrote:
> Charan, does the fix previously attached seem acceptable to you? Any
> additional feedback? Thanks.
First, thanks for taking this patch to upstream.
A comment in code snippet is checking just 'high wmark' pages might
succeed here but can fail in the immediate kswapd sleep, see
prepare_kswapd_sleep(). This can show up into the increased
KSWAPD_HIGH_WMARK_HIT_QUICKLY, thus unnecessary kswapd run time.
@Jaroslav: Have you observed something like above?
So, in downstream, we have something like for zone_watermark_ok():
unsigned long size = wmark_pages(zone, mark) + MIN_LRU_BATCH << 2;
Hard to convince of this 'MIN_LRU_BATCH << 2' empirical value, may be we
should atleast use the 'MIN_LRU_BATCH' with the mentioned reasoning, is
what all I can say for this patch.
+ mark = sysctl_numa_balancing_mode & NUMA_BALANCING_MEMORY_TIERING ?
+ WMARK_PROMO : WMARK_HIGH;
+ for (i = 0; i <= sc->reclaim_idx; i++) {
+ struct zone *zone = lruvec_pgdat(lruvec)->node_zones + i;
+ unsigned long size = wmark_pages(zone, mark);
+
+ if (managed_zone(zone) &&
+ !zone_watermark_ok(zone, sc->order, size, sc->reclaim_idx, 0))
+ return false;
+ }
Thanks,
Charan
