From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0223CC71136 for ; Thu, 12 Jun 2025 08:28:00 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 94CE06B008C; Thu, 12 Jun 2025 04:28:00 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 924056B0092; Thu, 12 Jun 2025 04:28:00 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 839576B0093; Thu, 12 Jun 2025 04:28:00 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 65D7B6B008C for ; Thu, 12 Jun 2025 04:28:00 -0400 (EDT) Received: from smtpin12.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id EAF55BE327 for ; Thu, 12 Jun 2025 08:27:59 +0000 (UTC) X-FDA: 83546070678.12.E8A4E46 Received: from out-172.mta1.migadu.com (out-172.mta1.migadu.com [95.215.58.172]) by imf20.hostedemail.com (Postfix) with ESMTP id 420E51C0008 for ; Thu, 12 Jun 2025 08:27:58 +0000 (UTC) Authentication-Results: imf20.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=nmPzjN15; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf20.hostedemail.com: domain of hao.ge@linux.dev designates 95.215.58.172 as permitted sender) smtp.mailfrom=hao.ge@linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1749716878; 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:in-reply-to:references:references:dkim-signature; bh=DkwHp5gNVL4KbrY8qJCfk1r1LfLJg5q3t6hNJxRz8qU=; b=YfPmQ3of1jcjcKxJubOQ+nKJOXxxSVIuRtEXzcEgZAnA57VNShxgJqbuhZ8hC3uePBlE99 9nKjDuZxvZUBRM/ImxGFkeZdIx/+fO9a6y8YwuTb+zvwehGfQrs+w93jBhKQz/Yaj/QM7h yRTGYmOSMWcr6b8PMhI5YlENLQ2Q4oo= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1749716878; a=rsa-sha256; cv=none; b=8JdkqEE+o7hzKYvXx2Pu1I5X9WDyOix1a3z655Q84G8xZZuLCJNXL3+BZTyA58iwBWXg65 IrLpxiDvRjn2uzH11d3o0Xv3wYyXmmG7RUj5eMW1IQDiZ2+nC2tnjk7IPSDKJatBo0hLu5 cCnwPCOJ1AcEEeZ8UYmM/S/lskU1mxg= ARC-Authentication-Results: i=1; imf20.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=nmPzjN15; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf20.hostedemail.com: domain of hao.ge@linux.dev designates 95.215.58.172 as permitted sender) smtp.mailfrom=hao.ge@linux.dev X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1749716876; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=DkwHp5gNVL4KbrY8qJCfk1r1LfLJg5q3t6hNJxRz8qU=; b=nmPzjN15kNg2zZxVlReQNakgS5TF3ho91Ph6hVAfiA4oJKSrWfJCp+pQEPZJtlhCTA4Lyu 0cRw1Owdsye3SJJjmFPVqo6b2hHxZzWDOoiQ3NswjOECaZ5DWipIDY5grB5UAaXWwwG2ly 2xJVBI8AEgg5oaEnRvQhSiqvPS/z6Mc= From: Hao Ge To: Andrew Morton , David Hildenbrand , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Suren Baghdasaryan , Mike Rapoport , Richard Henderson , Matt Turner , Dennis Zhou , Tejun Heo , Christoph Lameter , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , Kent Overstreet Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-alpha@vger.kernel.org, linux-s390@vger.kernel.org, Hao Ge , Hao Ge Subject: [PATCH 1/5] mm/Kconfig: add ARCH_NEEDS_WEAK_PER_CPU option Date: Thu, 12 Jun 2025 16:27:26 +0800 Message-Id: In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-Stat-Signature: gqtwkkoe66c6jnejawt7hx9ax8ya9dek X-Rspamd-Queue-Id: 420E51C0008 X-Rspam-User: X-Rspamd-Server: rspam06 X-HE-Tag: 1749716878-842291 X-HE-Meta: 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 XN7pVm8F ENjlctHaq5P9I+Ct3OIo6CpRZOfGlgGOFzn+SnsYn2beLXvNGtiPfc204KI1DTxntM1iKHKWuAtBWGjWfCfIbZbgegvGixila3n67gLmCmoid8q1II/eFVS8GTMXsQG/hK5+IqpMzu4VRQ/QD42LVAWYVJdh1y+vVhL7WrRWuVdKxSyORN2qCa216EqUqcZ9fDA3OrxtP+Yfk+k4cS83akXwo1NYl50mAXzgFcP19LsAIQQ5kzgLer4yZtg== 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: From: Hao Ge Recently discovered this entry while checking kallsyms on ARM64: ffff800083e509c0 D _shared_alloc_tag If ARCH_NEEDS_WEAK_PER_CPU is not defined((it is only defined for s390 and alpha architectures),there's no need to statically define the percpu variable _shared_alloc_tag. As the number of CPUs increases,the wasted memory will grow correspondingly. Therefore,we need to implement isolation for this purpose. However,currently ARCH_NEEDS_WEAK_PER_CPU is a #define and is enclosed within the #if defined(MODULE) conditional block. When building the core kernel code for s390 or alpha architectures, ARCH_NEEDS_WEAK_PER_CPU remains undefined (as it is gated by #if defined(MODULE)).However,when building modules for these architectures,the macro is explicitly defined. Therefore,we need to make ARCH_NEEDS_WEAK_PER_CPU a Kconfig option. And replace all instances of ARCH_NEEDS_WEAK_PER_CPU in the kernel code with MODULE_NEEDS_WEAK_PER_CPU,gated by #ifdef CONFIG_ARCH_NEEDS_WEAK_PER_CPU.Then,when defining the percpu variable _shared_alloc_tag,wrap it with the CONFIG_ARCH_NEEDS_WEAK_PER_CPU condition. Therefore,we should add the ARCH_NEEDS_WEAK_PER_CPU option to the mm Kconfig file. Suggested-by: Suren Baghdasaryan Signed-off-by: Hao Ge --- mm/Kconfig | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/mm/Kconfig b/mm/Kconfig index e113f713b493..36bb4d6fd360 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -929,6 +929,10 @@ config ARCH_SUPPORTS_PUD_PFNMAP def_bool y depends on ARCH_SUPPORTS_HUGE_PFNMAP && HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD +# s390 and alpha be enabled,see comments for DECLARE_PER_CPU_SECTION +config ARCH_NEEDS_WEAK_PER_CPU + bool + # # UP and nommu archs use km based percpu allocator # -- 2.25.1