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Thu, 03 Sep 2026 07:41:57 +0000 X-Mizu-Trace-ID: 40945f90da2aaa8b X-Migadu-Flow: FLOW_OUT Date: Thu, 3 Sep 2026 15:41:51 +0800 From: Baoquan He To: "Barry Song (Xiaomi)" Cc: akpm@linux-foundation.org, axelrasmussen@google.com, baolin.wang@linux.alibaba.com, chenridong@xiaomi.com, david@kernel.org, hannes@cmpxchg.org, kasong@tencent.com, lianux.mm@gmail.com, linux-kernel@vger.kernel.org, linux-mm@kvack.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 Subject: Re: [PATCH v2 2/2] mm/mglru: make retry logic explicit in isolate_folios() Message-ID: References: <20260903070500.76379-1-baohua@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20260903070500.76379-1-baohua@kernel.org> X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: A25BFC0009 X-Stat-Signature: 8i9fdchieuoqr1eh384wmy8z9kgxsbrx X-Rspam-User: X-HE-Tag: 1788421318-486798 X-HE-Meta: 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 UEtL9Jur ie9719EZsJMy9LGPY9Q+t9wicH/B8caDo7t5RISy7xw4BT+xhRAsesyOHJgezFv2l8dGO22iCAa12kGqBbIg8qVvKjEXixL0hBxcHlezTtIfTZBoKuwxsVt+nD4pC+8dYYBusYDWoOepiVAm3wYdk+mX8k1I8JrxLba0HXFUgzPjIL1Npj/S9obE5ZeCeEehgbCrVFpSDsunchC/OGIV2zNBx5pjNtqv8SrzfqttcEeiEP2X+V/T7pPLQOHpvFlVcI23pk4qDEoaRhAhPhrZWWUz7B4bZ3Ldp+jEfvqTIA8KT/CPuBF73bRhaY8kocuHBYXT5h49YM19jVZdiam/iDFFPJIZOsI0WnAXexGyCBzvJTXUk9vhVVzgq4dGAfooCTx929eXSdmY75tym/XZ62kBt8KCCFNM0zVAZZ035TFy6l4cnQHeCcqGU4ZnP0WV3I81UB+fyXu6qLl3/b9tr68mVU2P/jNgP4U75 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 09/03/26 at 03:05pm, Barry Song (Xiaomi) wrote: > On Thu, Sep 3, 2026 at 9:27 AM Baoquan He wrote: > > > [...] > > > > Thanks, Barry. These number is very convincing. The retry for swappiness > > 0 is worthy. Then the patchset feels like doing two things: refactoring > > the for() loop; improving the eviction for swappiness 0/201 by adding a > > retry and this also makes them be consistent with (1, 200). While the > > cover letter subject, patch 1 and patch 2 feels like it's not easy to > > match them to the corresponding part. Maybe merging them to one patch, > > or rearranging them? Just personal opinion. > > > > Hi Baoquan, > > Thanks very much for your suggestions and review. > We have two patches: > > 1. `mm/mglru: make type fallback logic explicit in isolate_folios()` > 2. `mm/mglru: make retry logic explicit in isolate_folios()` > > One handles fallback, while the other handles retry. I think this > separation makes the logic clearer. Could we keep the current > separation? Yeah, it's also fine to me. Thanks for the effort. > > But we may really need Andrew's kind help to squash the change > you found below: > > > From 1fb8046662a8b23be1b87a21cc9964e9ff9e1eb0 Mon Sep 17 00:00:00 2001 > From: "Barry Song (Xiaomi)" > Date: Thu, 3 Sep 2026 14:48:52 +0800 > Subject: [PATCH] mm: revert slight behavior change for swappiness 1-200 > > Baoquan's review found that we unexpectedly introduced a slight behavior > change for swappiness 1-200. We could now have a case like: > > 1. First scan -> `scanned != 0` > 2. Second scan -> `scanned = 0` > 3. Type fallback > > Step 3 was impossible before. Let's remove this possibility. > > Reported-by: Baoquan He > Closes: https://lore.kernel.org/linux-mm/apfZQE1X6zGAsBb_@fedora/ > Signed-off-by: Barry Song (Xiaomi) > --- > mm/vmscan.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/vmscan.c b/mm/vmscan.c > index bf2786c7247d..ba7adf36e69f 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -4939,7 +4939,7 @@ static int isolate_folios(unsigned long nr_to_scan, struct lruvec *lruvec, > * We are running out of the current reclaim type. Fall back to > * the other type if allowed. > */ > - if (!scanned && type_fallback_allowed) { > + if (!scanned && !tried && type_fallback_allowed) { > type = !type; > tried = true; > type_fallback_allowed = false; > -- > 2.39.3 (Apple Git-146) >