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b=fevBbZWW+amNTaTyKMVEGcATHJGI5beCyHSrNicjKpiIEwqwkPh/z0cIoe3sMBOEF 9KpGqhtEFq0bU7LJzRPro+xlky95JCucz80W5KK1l7KFP6+a4UbvOddg/RjiUMRrBc TnJmst4YvoB1b0exji4XGaiDzIYHqxZdQizL+lY9YRCXPqsiUNa4Iwizpjdil6w8kp avB7IiJOReUiZACrj/lPByfzfPgo+MU9KSfdz4bAzD5EbUs+mS2HRvW6EaIzmE8J07 jvv3I3rp4Q5xcvMk2ehvO5RHd+1nyNoGg6Bez7jfcnci4AcbssWI275h4ttA7+QWrP 1r5bMWvNKzJAA== Date: Fri, 22 May 2026 16:42:34 +0100 From: Lorenzo Stoakes To: Barry Song Cc: Matthew Wilcox , akpm@linux-foundation.org, bhe@redhat.com, chentao@kylinos.cn, chrisl@kernel.org, david@kernel.org, jack@suse.cz, kasong@tencent.com, kunwu.chan@gmail.com, liam@infradead.org, lianux.mm@gmail.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, liyangouwen1@oppo.com, loongarch@lists.linux.dev, mhocko@suse.com, nphamcs@gmail.com, nzzhao@126.com, pfalcato@suse.de, rppt@kernel.org, shikemeng@huaweicloud.com, surenb@google.com, vbabka@kernel.org, wanglian@kylinos.cn, youngjun.park@lge.com Subject: Re: [PATCH v2 0/5] mm: reduce mmap_lock contention and improve page fault performance Message-ID: References: <20260522023305.98223-1-baohua@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 4DE1A2000C X-Stat-Signature: fuigzgzfc4xg9dcy8wkcemrpfbbuhfuy X-Rspam-User: X-HE-Tag: 1779464564-317707 X-HE-Meta: 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 6AJN9lGC F+woYv+dc/eghd2axX5LhUZmPm1tg7bRuUlP8BPzKjhXPimsoQ0ryJ44iA8YfwTIjGczofTrPEMHMMXCLkQB1LujaRNkr0cI4vALMuu+tFrP8/rZs78iASdGgnBBjnqh2UxzeIda96OdjI8OnQIKT8JMduyZGjCbkbBE+/SQyXo+GbF+OvOgOOt47jg2VrhZOvns3aNX6TCBb7zH7h6x+ciuiukDqI+4CoJhpnMsc7yf1PTkx0MDGNwKgJvPrjO1eFJtLTas9+NToWkMhcEpAo6VoXwsGjJUFXZFBgyqOHUNpqYHxwlN6LPEW2Wy+SPI9sbO2bW/75n28rw7QJQ5krrdU1awpDH8T+SJiyWO/t8bq0R45uIJoHtxvGnF00RGLenFyaS1XIwNDVC6UvQEOuH4zZou1gkKFM6HCbrXDr87NUBmZRs55z587mrX8uyaVca7mEGbqhUWuTH+6Fqc5BcwHml5GbwxkL07m Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Fri, May 22, 2026 at 09:48:35PM +0800, Barry Song wrote: > On Fri, May 22, 2026 at 9:36 PM Barry Song wrote: > > > > On Fri, May 22, 2026 at 9:09 PM Matthew Wilcox wrote: > > > > > > On Fri, May 22, 2026 at 10:33:05AM +0800, Barry Song (Xiaomi) wrote: > > > > need to touch `filemap.c` at all (probably because you are already > > > > maintaining `filemap.c` perfectly): > > > > > > I'm going to give you one chance to apologise for that. > > > > Apologies if my wording caused any misunderstanding. > > That was not my intention at all. > > > > What I meant is that filemap.c already has a very > > solid design. > > > > For memory.c, I had to touch several places for the > > blacklist; otherwise, the kernel would hang. > > > > But for filemap.c, I basically didn't need to touch > > anything, and preliminary testing shows no issues after > > moving it from the whitelist to the blacklist. This is > > Sorry, I feel I may be causing some misunderstanding > again. > > By "whitelist", I mean I used to allow certain cases > to use per-vma retry. > > By "blacklist", I mean I am now moving to disallow > certain cases from using per-vma retry. > > Right now, I have to add several cases in memory.c > to the blacklist; otherwise, the kernel would hang. > > But it seems that everything in filemap.c is fine so > far based on testing. > > I'm not sure if I've explained things clearly. Please > let me know if anything is still unclear or insufficient. Barry - this thread is completely out of hand and getting _rapidly_ unproductive. It's certainly about as clear as mud where we stand right now, so here's my suggestion - let's just stop adding to the noise here :) and instead, you take the approach suggested by Suren at LSF and send that as an _RFC_ series. That way we can look at that and hopefully actually circle in on a solution rather than have endless sub threads and sub discussions :) It's far too sunny out in the UK right now for that ;) Thanks, Lorenzo