On Wed, 22 Jan 2025 at 22:44, Japin Li <japi...@hotmail.com> wrote: > On Wed, 22 Jan 2025 at 17:02, Yura Sokolov <y.soko...@postgrespro.ru> wrote: >> I believe, I know why it happens: I was in hurry making v2 by >> cherry-picking internal version. I reverted some changes in >> CalcCuckooPositions manually and forgot to add modulo >> PREV_LINKS_HASH_CAPA. >> >> Here's the fix: >> >> pos->pos[0] = hash % PREV_LINKS_HASH_CAPA; >> - pos->pos[1] = pos->pos[0] + 1; >> + pos->pos[1] = (pos->pos[0] + 1) % PREV_LINKS_HASH_CAPA; >> pos->pos[2] = (hash >> 16) % PREV_LINKS_HASH_CAPA; >> - pos->pos[3] = pos->pos[2] + 2; >> + pos->pos[3] = (pos->pos[2] + 2) % PREV_LINKS_HASH_CAPA; >> >> Any way, here's v3: >> - excess file "v0-0001-Increase..." removed. I believe it was source >> of white-space apply warnings. >> - this mistake fixed >> - more clear slots strategies + "8 positions in two cache-lines" strategy. >> >> You may play with switching PREV_LINKS_HASH_STRATEGY to 2 or 3 and see >> if it affects measurably. > > Thanks for your quick fixing. I will retest it tomorrow.
Hi, Yura Sokolov Here is my test result of the v3 patch: | case | min | avg | max | |-------------------------------+------------+------------+------------| | master (44b61efb79) | 865,743.55 | 871,237.40 | 874,492.59 | | v3 | 857,020.58 | 860,180.11 | 864,355.00 | | v3 PREV_LINKS_HASH_STRATEGY=2 | 853,187.41 | 855,796.36 | 858,436.44 | | v3 PREV_LINKS_HASH_STRATEGY=3 | 863,131.97 | 864,272.91 | 865,396.42 | It seems there are some performance decreases :( or something I missed? -- Regrads, Japin Li
