From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta0.migadu.com (out-251.mta0.migadu.com [91.218.175.251]) (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 4AAC43BAD9F for ; Thu, 13 Aug 2026 09:34:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.251 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786613647; cv=none; b=h9nH9U/H9iP8h4K95DIX/WJ0UL/2dMew6uWOks3MqJhoa3+g074er+Xp0IExN0Xp3MCWsIOi8fU+roCV7/EEp5rPDCdKomcYktc26OZj/DHRLAaYFxda2NZYn1zQiYeaOl0r/n/yqVWugikLZ1IOjozAg0q8SjzUP3X1CDINJIY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786613647; c=relaxed/simple; bh=tn8UuuKtkL7oFhh/U1B37Ptewe1hVf6VZJL600BRXaI=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=Vkmdw+R1LSgxRppv56LL3tfYqeoMPyQ+bVbpRJy2O49HjPbhk84o4vpWTCUqcOEAGs1XW23E5MATio5dEFjG+Envzx79cFCMukJVJTxyHWY/Z7xCYF8AP1d+ERDiezd3aieLCnaIvH8IX3SV8zhoZ74R46kk9mS4U1wHZS9Xy5o= 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=ns2Gado5; arc=none smtp.client-ip=91.218.175.251 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="ns2Gado5" X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=tn8UuuKtkL7oFhh/U1B37Ptewe1hVf6VZJL600BRXaI=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1786613643; v=1; x=1787218443; b=ns2Gado5My663OsOlq6xH4Q/bnQS1hmgLKSrdDPs8vx+UeedXhTT7Z0gxpKI9yKmAXOGbsyA uIGKipHZfUJxhP85ftIQR51fkDMgWLpoDR8aMYRDnemhSegKfH/5aeto5uMYjvBeekVqzl6OPB8 7mfJQgGJ8O4OxlxSlVIeuX98= X-Envelope-To: linux-kernel@vger.kernel.org Received: from localhost.localdomain (116.128.244.169) by smtp.migadu.com with ESMTPS id 7cdc111fd4b862bb; Thu, 13 Aug 2026 09:34:02 +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 1/3] alloc_tag: skip percpu counter allocation when profiling is disabled Date: Thu, 13 Aug 2026 17:34:19 +0800 Message-Id: <20260813093421.135230-2-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 After shutdown_mem_profiling() clears mem_profiling_support, needs_section_mem() returns false, so later modules have their codetag section placed as regular data and never enter the alloc_tag maple tree. codetag_load_module() still called load_module(), which allocated a percpu counter for every tag; release_module_tags() could not find these modules on unload, so the counters leaked. Return CODETAG_MODULE_EXCLUDED from load_module() when profiling is off: codetag_module_init() drops the module's cmod and no counters are allocated. codetag_unload_module() now always calls free_section_mem(), since an excluded module may still hold a reserved section. Fixes: 4835f747d3ed ("alloc_tag: support for page allocation tag compression") Signed-off-by: Hao Ge --- include/linux/codetag.h | 4 ++++ lib/codetag.c | 8 +++++--- mm/alloc_tag.c | 8 ++++++-- 3 files changed, 15 insertions(+), 5 deletions(-) diff --git a/include/linux/codetag.h b/include/linux/codetag.h index a25a085c2df1..88081c618673 100644 --- a/include/linux/codetag.h +++ b/include/linux/codetag.h @@ -52,6 +52,10 @@ struct codetag_type_desc { #endif }; +/* module_load() return values */ +#define CODETAG_MODULE_LOAD 0 /* module loads with its tags */ +#define CODETAG_MODULE_EXCLUDED 1 /* module loads without its tags */ + struct codetag_iterator { struct codetag_type *cttype; struct codetag_module *cmod; diff --git a/lib/codetag.c b/lib/codetag.c index a9cda4c962a3..8506ecab9ea7 100644 --- a/lib/codetag.c +++ b/lib/codetag.c @@ -238,9 +238,10 @@ static int codetag_module_init(struct codetag_type *cttype, struct module *mod) } up_write(&cttype->mod_lock); - if (err < 0) { + if (err) { + /* Error or excluded: cmod is dropped, free it. */ kfree(cmod); - return err; + return err < 0 ? err : 0; } return 0; @@ -388,7 +389,8 @@ void codetag_unload_module(struct module *mod) ++cttype->content_id; } up_write(&cttype->mod_lock); - if (found && cttype->desc.free_section_mem) + /* an excluded module may still hold section memory */ + if (cttype->desc.free_section_mem) cttype->desc.free_section_mem(mod, true); } mutex_unlock(&codetag_lock); diff --git a/mm/alloc_tag.c b/mm/alloc_tag.c index 0a7b657fe2de..461fa87fbb0b 100644 --- a/mm/alloc_tag.c +++ b/mm/alloc_tag.c @@ -977,9 +977,13 @@ static int load_module(struct module *mod, struct codetag *start, struct codetag struct alloc_tag *stop_tag; struct alloc_tag *tag; + /* Profiling disabled: load the module but exclude its tags. */ + if (!mem_profiling_support) + return CODETAG_MODULE_EXCLUDED; + /* percpu counters for core allocations are already statically allocated */ if (!mod) - return 0; + return CODETAG_MODULE_LOAD; start_tag = ct_to_alloc_tag(start); stop_tag = ct_to_alloc_tag(stop); @@ -1002,7 +1006,7 @@ static int load_module(struct module *mod, struct codetag *start, struct codetag */ kmemleak_ignore_percpu(tag->counters); } - return 0; + return CODETAG_MODULE_LOAD; } static void replace_module(struct module *mod, struct module *new_mod) -- 2.25.1