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a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1768232807; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:references; bh=/2Fpx5sMln+4uvsY6IoIKQrv1w7KPnbD9F8QJS3ZSO8=; b=tQfbNREJ7PBMCo8BJNe5NvTFxORQGDYjTCL55v0jy/2Jhb9dKgbJ4VdLH5Je+Qh4ykdBHd Ou9rfOXE/lGCvXLGhv4ifOgXDEl/lGrPQIWYe4gbmIcbJtZa5aoVGt2nsUHN3OZrJxLy2u f9lZOXe0T/767xjk49AHkfnsPjGRo1U= Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 73310497; Mon, 12 Jan 2026 07:46:39 -0800 (PST) Received: from 010265703453.arm.com (unknown [10.57.48.115]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id B7BFF3F694; Mon, 12 Jan 2026 07:46:43 -0800 (PST) From: Robin Murphy To: m.szyprowski@samsung.com, akpm@linux-foundation.org, vbabka@suse.cz, david@kernel.org Cc: bhe@redhat.com, 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: [PATCH 0/3] dma-mapping: Improve atomic pool behaviour Date: Mon, 12 Jan 2026 15:46:35 +0000 Message-Id: X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 5CB664000F X-Stat-Signature: xzrc18tkamp53odmkahohu5m7gmg3boe X-Rspam-User: X-HE-Tag: 1768232807-640323 X-HE-Meta: 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 KRHY/kHR pFHuX50aa+Nsy7F2/Q19K3gK6WqpEnDl68kUi1r1O2qKo++yrVJBvO2dEAZBwEaidbIBD2IDAYGSw+fdtbRXocqNwtmWTcgWrsQnYVSNvqR6TiRV8ElemMicv0RlfZMcI6gN2UM2WQl4nZdmvW+5bZZ+FYOGv+9qaRjB9kVyFIV6dKVsl6e6/tUOEAszNRNAnb3BxRyzhzXrCdqI= 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: 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. I guess this could go via either the dma-mapping or mm tree, whichever maintainers prefer. Thanks, Robin. [1] https://lore.kernel.org/linux-iommu/20260112065857.3137331-1-vladimir.kondratiev@mobileye.com/ [2] https://lore.kernel.org/linux-iommu/20260112104749.4132641-1-s-adivi@ti.com/ Robin Murphy (3): dma/pool: Improve pool lookup mm_zone: Generalise has_managed_dma() dma/pool: Avoid allocating redundant pools include/linux/mmzone.h | 9 +++++---- kernel/dma/pool.c | 27 ++++++++++++++++++--------- mm/page_alloc.c | 8 ++------ 3 files changed, 25 insertions(+), 19 deletions(-) -- 2.34.1