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Fri, 21 Aug 2026 01:45:17 +0000 X-Mizu-Trace-ID: 608958cb15c913ce X-Migadu-Flow: FLOW_OUT Message-ID: <4838e4ff-e982-4347-9972-741e08dd1bd0@linux.dev> Date: Fri, 21 Aug 2026 09:45:10 +0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 3/3] mm/mglru: retry the same type once if isolation fails due to races To: "Barry Song (Xiaomi)" , akpm@linux-foundation.org, linux-mm@kvack.org Cc: axelrasmussen@google.com, baolin.wang@linux.alibaba.com, baoquan.he@linux.dev, chenridong@xiaomi.com, david@kernel.org, hannes@cmpxchg.org, kasong@tencent.com, lianux.mm@gmail.com, linux-kernel@vger.kernel.org, ljs@kernel.org, lyugaofei@xiaomi.com, mhocko@kernel.org, qi.zheng@linux.dev, shakeel.butt@linux.dev, stevensd@chromium.org, wangzicheng@honor.com, weixugc@google.com, yuanchu@google.com References: <20260820045603.68809-1-baohua@kernel.org> <20260820045603.68809-4-baohua@kernel.org> From: Ridong Chen In-Reply-To: <20260820045603.68809-4-baohua@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspam-User: X-Stat-Signature: hamhex8bix1b9mxf35yykmjcgdw5hfr1 X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: 7AB4920008 X-HE-Tag: 1787276718-234768 X-HE-Meta: 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 9hX0BoaU oQF4yu6pqrkeG0D4gmFcC+Jvx+5piux6XgiqDRs69MJGGDd/q2p86GpDtSAIApRL7LAyAiqqLws6eUFP3QbZQ9yms/v4XXxPKVDgGad2ysA/6M8JxuWuLyRJPPu2o2ylB0nxYL1Tlxm6KJwc0w3/d5cHVKwomSfhsBd7gI6Y3l2azObCEp8ypCG9tHgWx6FPqT6Wdey4JRpBcOWUjpfVcTaQeLEButx24jRLW6PuXTt5Gx3i1SuqjWAZgkto/T72tXFYbXaQ2jHy3ugM1NC46DMxTMopG9h8CvUbSIBg2iRo2mayFZ6+OCLW11aYulYgYQEHdBpAx2AgDA4aWfmQMaB/Y/V4PASwFmzQD5nJc/jSPQZWQkPydrVbexQ== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 8/20/2026 12:56 PM, Barry Song (Xiaomi) wrote: > If we are not exhausted (i.e., there are still folios in the > reclaimable generations) but fail to isolate any folios due to > promotions, protections, or races, retry once more to avoid going > through the outer loop again. > > Signed-off-by: Barry Song (Xiaomi) > --- > mm/vmscan.c | 10 +++++++++- > 1 file changed, 9 insertions(+), 1 deletion(-) > > diff --git a/mm/vmscan.c b/mm/vmscan.c > index 1f2e574b0061..1f302386d8ab 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -4862,7 +4862,7 @@ static int isolate_folios(unsigned long nr_to_scan, struct lruvec *lruvec, > bool type_fallback_allowed = !is_single_type_reclaim(swappiness); > int type = get_type_to_scan(lruvec, swappiness); > int total_scanned = 0, scanned, tier; > - bool exhausted; > + bool exhausted, tried = false; > > retry: > tier = get_tier_idx(lruvec, type); > @@ -4885,6 +4885,14 @@ static int isolate_folios(unsigned long nr_to_scan, struct lruvec *lruvec, > type_fallback_allowed = false; > goto retry; > } > + /* > + * We are not exhausted, but failed to isolate any folios due to > + * promotions, protections, or races. Retry once to avoid a larger loop. > + */ > + if (!exhausted && !tried) { > + tried = true; > + goto retry; > + } > > return total_scanned; > } LGTM. Reviewed-by: Ridong Chen -- Best regards Ridong