From nobody Tue Feb 10 21:41:09 2026 Received: from fanzine2.igalia.com (fanzine.igalia.com [178.60.130.6]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5C0E815099A; Mon, 22 Apr 2024 14:21:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=178.60.130.6 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713795665; cv=none; b=bD6jSYtho7n4LQfdCU8fvG/I3mWU7tWvtWq9qrAWU/qnKTE95qN/iycdh+igo5KCjyfVru0cwk/2CZGLmaoOa4G5bJwhxMmv/08HLuTwD747j6LBvAnqCynQrfaLUED9mPNbO7UP51ZS/5dFHitZFuhYt5oWVSISdCEcBxcJNxA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713795665; c=relaxed/simple; bh=kRCc2qB+QRN81Y9A6rydtQv4DOylAlEkQPIWVCVxyh0=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version:Content-Type; b=omt2vBPGM4NY/OIK4mlDFeY5XcVqGq2Q72wF/tcfcT2FB5dDviMR+1hJMWArD97CHRY/KzyeX3v86OvEqHkl/oMB1O9d6T0ddoNO/ARWdln+Ot0k5Csee2szE/34b6GRCV7EFwGxNkizHy2iaNkQ9OyzChJrpw7nabAmZzkvi7s= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=igalia.com; spf=pass smtp.mailfrom=igalia.com; dkim=pass (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b=ms1kULvc; arc=none smtp.client-ip=178.60.130.6 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=igalia.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=igalia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b="ms1kULvc" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Content-Transfer-Encoding:Content-Type:MIME-Version:Message-ID: Date:Subject:Cc:To:From:Sender:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: In-Reply-To:References:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=gDB1GmbLM1RgLFgDDRHYfTCreFTNn/hu28SEK8oaIj0=; b=ms1kULvct7a4ce6WyMgmW1r7nl cfRnf6+dSPUkoWok5LeTV6xdjjUPDGIGDB65WOhPGGg3lxvqSkuQYCTyvJu8//VZ1Qs2oOHHbm+7O 9sYNCsJu1RGwd/R8LJNK+uoGdC+OYuNjgvYWjlEgLW4+rQ/xYbmhnqED72RkJM/pNA2bYrpjMJJ+O HdgrA5HBqJ0w1tctOJsEo1XDl1L8LcrPMWlFT6sbv4lPo6MaYy92wuvSxC1XCqkFYhQAxc5whQHBn Lf+ydJ1HccDQRkx+zjZe0BQpTaPSz2xGS75VAzXB5gk8zW0a3cOeCfB5Gh0p8HCil2iEGY4y82TzM lf52I8CA==; Received: from [179.234.232.152] (helo=morissey..) by fanzine2.igalia.com with esmtpsa (Cipher TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim) id 1ryuWz-007HEu-GN; Mon, 22 Apr 2024 16:20:30 +0200 From: =?UTF-8?q?Ma=C3=ADra=20Canal?= To: Jonathan Corbet , Andrew Morton , Josh Poimboeuf , Tejun Heo , David Hildenbrand , Wei Yang , Michal Hocko , Johannes Weiner , Minchan Kim , Huang Ying , Mel Gorman , Dan Williams Cc: linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, kernel-dev@igalia.com, =?UTF-8?q?Ma=C3=ADra=20Canal?= Subject: [PATCH] mm: Update shuffle documentation to match its current state Date: Mon, 22 Apr 2024 11:18:40 -0300 Message-ID: <20240422142007.1062231-1-mcanal@igalia.com> X-Mailer: git-send-email 2.44.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Commit 839195352d82 ("mm/shuffle: remove dynamic reconfiguration") removed the dynamic reconfiguration capabilities from the shuffle page allocator. This means that, now, we don't have any perspective of an "autodetection of memory-side-cache" that triggers the enablement of the shuffle page allocator. Therefore, let the documentation reflect that the only way to enable the shuffle page allocator is by setting `page_alloc.shuffle=3D1`. Signed-off-by: Ma=C3=ADra Canal Reviewed-by: David Hildenbrand --- Documentation/admin-guide/kernel-parameters.txt | 10 ++++------ mm/Kconfig | 7 +++---- 2 files changed, 7 insertions(+), 10 deletions(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentatio= n/admin-guide/kernel-parameters.txt index 902ecd92a29f..924bb8ddd8a8 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -4170,13 +4170,11 @@ =20 page_alloc.shuffle=3D [KNL] Boolean flag to control whether the page allocator - should randomize its free lists. The randomization may - be automatically enabled if the kernel detects it is - running on a platform with a direct-mapped memory-side - cache, and this parameter can be used to - override/disable that behavior. The state of the flag - can be read from sysfs at: + should randomize its free lists. This parameter can be + used to enable/disable page randomization. The state of + the flag can be read from sysfs at: /sys/module/page_alloc/parameters/shuffle. + This parameter is only available if CONFIG_SHUFFLE_PAGE_ALLOCATOR=3Dy. =20 page_owner=3D [KNL,EARLY] Boot-time page_owner enabling option. Storage of the information about who allocated diff --git a/mm/Kconfig b/mm/Kconfig index b1448aa81e15..f30a18a0e37d 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -333,10 +333,9 @@ config SHUFFLE_PAGE_ALLOCATOR =20 While the randomization improves cache utilization it may negatively impact workloads on platforms without a cache. For - this reason, by default, the randomization is enabled only - after runtime detection of a direct-mapped memory-side-cache. - Otherwise, the randomization may be force enabled with the - 'page_alloc.shuffle' kernel command line parameter. + this reason, by default, the randomization is not enabled even + if SHUFFLE_PAGE_ALLOCATOR=3Dy. The randomization may be force enabled + with the 'page_alloc.shuffle' kernel command line parameter. =20 Say Y if unsure. =20 --=20 2.44.0