From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta0.migadu.com (out-2.mta0.migadu.com [91.218.175.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 939B43D170E for ; Thu, 13 Aug 2026 09:34:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.2 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786613661; cv=none; b=GkDDyWBf2/vbVBiOSvTToHgd7XPPiPWN4rb3PK9TJidlFxDXZJqBv8hjGxcVgZd5jawyASyO7yCrGyMBe5UTrrnqBp+aWhc3ya3727yqCj7Hku2i05703B8FM0mC7vaoAdGMAzVOOvtzXGr2oqrnqVY6c0bHTXD3/abQpDmlt9s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786613661; c=relaxed/simple; bh=hPN6+ldNa92yVfg5JXt1vgfrSMYfaiItc5ke6iFo9is=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=AYEHGYVQuhaGyYNujsgr7Zboy+H7wm4ttI53enAXglDAckBPZpPTMgM9TFZqsqSpT/B/1569WsnDkg3VmfGX6Xv5LU8aT6vB7FPHl31KQjWQ4WbvTYVVevTw47dZGQ7I1zjh5v6bgjZeBo6HWRQmipkU4VuAAg5EHR9oDUAiJVk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=Ve/BuX7Y; arc=none smtp.client-ip=91.218.175.2 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="Ve/BuX7Y" X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=hPN6+ldNa92yVfg5JXt1vgfrSMYfaiItc5ke6iFo9is=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1786613655; v=1; x=1787218455; b=Ve/BuX7YWVqBo/ABZYgyXwpdHXANW8oh1K46WtEot5WlWwmlYaJrvYjXQhvPqtcxqNv57CDf J3fVIefYJeNAyVzqJeKfPvoOncCJ+do2gCvzPN3p5/YS+zYWDfd1LnSSeOla5eG+PQtsyl95qRp iuKV9mdSoApubKNnmXlRU5JM= X-Envelope-To: linux-kernel@vger.kernel.org Received: from localhost.localdomain (116.128.244.169) by smtp.migadu.com with ESMTPS id 20da645f262052b9; Thu, 13 Aug 2026 09:34:15 +0000 X-Migadu-Flow: FLOW_OUT From: Hao Ge To: Suren Baghdasaryan , Andrew Morton , Luis Chamberlain , Petr Pavlu , Daniel Gomez , Sami Tolvanen , Aaron Tomlin Cc: linux-modules@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Hao Ge Subject: [RFC PATCH 3/3] alloc_tag: remove /proc/allocinfo outside of mod_lock Date: Thu, 13 Aug 2026 17:34:21 +0800 Message-Id: <20260813093421.135230-4-hao.ge@linux.dev> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20260813093421.135230-1-hao.ge@linux.dev> References: <20260813093421.135230-1-hao.ge@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit shutdown_mem_profiling() calls remove_proc_entry() from reserve_module_tags(), which runs under mod_lock held for write. remove_proc_entry() waits for readers, and a reader takes mod_lock for read in allocinfo_start(): CPU0 (insmod) CPU1 (read /proc/allocinfo) ---------------- ---------------------------- reserve_module_tags() down_write(&mod_lock) [held] use_pde() [in_use++] allocinfo_start() down_read(&mod_lock) <- blocks shutdown_mem_profiling() remove_proc_entry() wait for in_use == 0 <- blocks Move remove_proc_entry() to a workqueue. Fixes: 4835f747d3ed ("alloc_tag: support for page allocation tag compression") Signed-off-by: Hao Ge --- mm/alloc_tag.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/mm/alloc_tag.c b/mm/alloc_tag.c index 7481180dadd2..b80f5a151f28 100644 --- a/mm/alloc_tag.c +++ b/mm/alloc_tag.c @@ -591,6 +591,13 @@ void pgalloc_tag_swap(struct folio *new, struct folio *old) put_page_tag_ref(handle_new); } +static void remove_allocinfo_file(struct work_struct *work) +{ + remove_proc_entry(ALLOCINFO_FILE_NAME, NULL); +} + +static DECLARE_WORK(remove_allocinfo_work, remove_allocinfo_file); + static void shutdown_mem_profiling(bool remove_file) { if (mem_alloc_profiling_enabled()) @@ -600,7 +607,7 @@ static void shutdown_mem_profiling(bool remove_file) return; if (remove_file) - remove_proc_entry(ALLOCINFO_FILE_NAME, NULL); + schedule_work(&remove_allocinfo_work); mem_profiling_support = false; } -- 2.25.1