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Wed, 14 Jan 2026 02:06:17 +0000 (UTC) Date: Wed, 14 Jan 2026 10:06:13 +0800 From: Baoquan He To: Robin Murphy Cc: m.szyprowski@samsung.com, akpm@linux-foundation.org, vbabka@suse.cz, david@kernel.org, iommu@lists.linux-foundation.org, linux-mm@kvack.org, vladimir.kondratiev@mobileye.com, s-adivi@ti.com, linux-kernel@vger.kernel.org, lorenzo.stoakes@oracle.com, Liam.Howlett@oracle.com, rppt@kernel.org, surenb@google.com, mhocko@suse.com, jackmanb@google.com, hannes@cmpxchg.org, ziy@nvidia.com Subject: Re: [PATCH 0/3] dma-mapping: Improve atomic pool behaviour Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 00CE6160006 X-Stat-Signature: xauwzgys937deie37z5r9p9jgdwowuhj X-Rspam-User: X-HE-Tag: 1768356387-315338 X-HE-Meta: U2FsdGVkX1+hOG+up1q6iTekC6k647L/BgnIXfMd+qf/vrnaagYr3SMzNnCbjl8LPMcXbuK8nU77KNHi9To4Q16e7eyI/itjGV2MskPZAS+CeckrpO0KJvT2HHiF4xOgJLndJeZWBfeaeuCT+MkCf5Vn/nbHQxWhd9du2s5aDzeAmgYQsYUx4j8bS8p74sTTogRgcJqYIPibBH9s/A6+5sEMr471+pVmWjJ+4DgRffHZ84aBgGHoMoLueSVfk/C9E9TTZvJIZwcbDBwP/BaaKKK2+Vct/585/kPDfng7ZbDUsKjWxFUHTwgoIxY/v/vBsAeEyeEbmPFSD7hspfErCZTGNsvp9wskU1QCHkwFG/MhFWLvvQ58yCoWB/CmWoP6CgqdZcZOEGNxfUN09m3Eao2ovqNE27K6w6m/Ky6YANRRudwAdJ4ivbd6gosT9+cOuxUa5/sp3KhsKOv9ACHyvSyVF3JKaHax5LmWEMqbZ0mJbwSVesHZg+o0gNF406pSoY6em+3DpU300w87dav0rJK9c5W5HhARZKs1OFZpiC0FVL10VJ4g9KO2YNeUBqJUyGYUwRM8Q9Te1fXAp87mQR4OyZ7+GP8XcjIhgtqAACs3HI7qQK9gNk2Gqh4Ou5alR36xOFjHq4xZ9TTpmtiUvGFQZsAM5biSBSReBFKlT3cgUTJyKPb9Kx6T0N4EXbW9pAEOYTVgh3jYZDgAa379z0XapDE2oJJZJqcTTw5DUT0JA0bDI2RsoDNtJvgiM7TsbazwkKk12N50zQj4blpT45CO+eeTQgykr4KgR2YqJ8fdeYtEujvpNivI58bNFdtQrTAe256qbX+anNJfGb6V9T22wY3DtyYTC8eUCaHzRbnvXEokL9jZ8fE0ent/n9zkvIFM0Mo8lI3jfCTrd1mpwB0udeO1Gk4NH1PAq1Hr/crp3VU1yeKkW7ibxyi8MsNEa1Sn8n0pWf3va5AR/ln y/z6878Y MoVQFGVIZflYK2KgqqxwIPpA2otYC+Zin+iwlFmCsxkPhJ8Z8WEgwiMJKVU+IBkDPBIHTqcOKKNWdNZB4teTPxQyNu02Se1dYJu2F+OASPcJabrD1KaooOSlPGL2I8Tnqr5T6iNr2OsQUik4xh/23rjwS5uSLJhBxyZRyhXp7x3e7sBG2CSpEIzNto5w1Vwcujt5fF06gPwDQ0776kqynVxk7cfXTGHjwKeKTPBIMGEOiMs8YYn4zvUgEhA7WAAOvt5/1+3afOaeT5HBKj7UCY2f3SKgR2/P+QJM2ne5V6EJswv3AnCl/BH2u+VjX6AqywOVgb9hR2KPwdTxwcfdaKl4wi06rObKCqvbEykVIEnLhq+EZx84zqQoNBFF1ZU9Kf4QF22HYo9eM8IHKg6fl0RYE5TV3MeFgdgqjW+fYQdzvpdgO23GTGyixn4QgZ5et19or8L8TjP8U7+MTVo1cxpEKgxeaLU3vtenN X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 01/12/26 at 03:46pm, Robin Murphy wrote: > Hi all, > > These days we have somewhat of a matrix of mm zones that may or may not > exist and may or may not be empty, which the per-zone atomic pool logic > doesn't actually handle all that well. It's not all that difficult to > improve robustness and reduce redundancy, so that's what this series > aims for. > > I initially wrote this just because I happened to be looking through the > boot log of one of my boards and had one of those out-of-the-blue > realisations of "hang on, why *is* it allocating pools for zones it > doesn't even have memory in?", but coincidentally, it seems that others > happened to notice related aspects around the same time[1][2]. This is > my attempt to sort it all out properly. Reviewed-by: Baoquan He