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 X-Spam-Level: X-Spam-Status: No, score=-20.4 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3325CC433DF for ; Fri, 16 Oct 2020 02:40:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D3B5C20EDD for ; Fri, 16 Oct 2020 02:40:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="UzPVodG7" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404263AbgJPCkt (ORCPT ); Thu, 15 Oct 2020 22:40:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57592 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404251AbgJPCkp (ORCPT ); Thu, 15 Oct 2020 22:40:45 -0400 Received: from mail-wm1-x341.google.com (mail-wm1-x341.google.com [IPv6:2a00:1450:4864:20::341]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C232FC061755 for ; Thu, 15 Oct 2020 19:40:43 -0700 (PDT) Received: by mail-wm1-x341.google.com with SMTP id 13so968495wmf.0 for ; Thu, 15 Oct 2020 19:40:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=MM4vknTStYRLkGZw4tEHhTyBDfVUaCowXRmIC2TIp+c=; b=UzPVodG7vA2ic1HH1rFJ9ZFcjIcafLiynej1hsfsW7Kk8wfH5gNDzFpgzEjh3lN58l k0dAp9bXU+cG3pzw3tHSGbuYEk2L7mtIYHUFm+JeveAYlOMp75+XCbhV8IOZtonrBENQ N3EuUEXsABr3wvBaELeeMCVuFKi/re3WS+eoQMSP1pOGXHnkEyafFQENqCfVkz8ZBh12 LEr/np5tTIRUXaDrf3a6Zu5AOPiFCvfr+ogI139Xbc2dsROxhWd1zDR87GC3eWDxiU15 Mgm+yz3mfYc2ggE+SKeJcFy7gWvizCM5fduQMpvrjIhdvXokKcUaTd0xrhi19exO0wq1 CZQw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=MM4vknTStYRLkGZw4tEHhTyBDfVUaCowXRmIC2TIp+c=; b=R7owW4X4faazngEk1MLHP/Ki9FzUmALc8dOHOmcv/MLyscAJ8uo200vvG0rkeJxbJu X/rk5bxyt6/UpYPS2WwN1cRyogtI6CpRZwArHhqL3O4Ya8FskD2Z1eR7bhpLJjrbWahK LvFbOQWELOvn1ieZ9127cgiUxgPU9HYJfS2aqCta/hFMG3WdyIhz1rHczfAEVV03UO3g 0TEZ6OIkepscg1WC5QcAiZAHQ1Z+R0t+bqBc3tMU0U8g2aMwg8Ak8o86SWGv51bQMOre 7QX7CY9eY759mEKv1uoRj0ZaaipC1TAx5id66mHygvn+I9m5NSDIx2jFR7wNWsp0RR+d dtPw== X-Gm-Message-State: AOAM531lSb7PiHzTneaeYB2ittdq3DyRWXjhfO1bBCULq9e+4zf9E3t0 GgWTsGRbVNnNq8TaRUiYc8aIhw== X-Google-Smtp-Source: ABdhPJzhEFMFksHr3z4YKmc2OKnKI/GGyeg8SX7OdlCeHKjZMM8NAVXhzJhEFVJQFXw7prbPniY0DA== X-Received: by 2002:a7b:c451:: with SMTP id l17mr1421587wmi.127.1602816042197; Thu, 15 Oct 2020 19:40:42 -0700 (PDT) Received: from localhost ([2a02:168:96c5:1:55ed:514f:6ad7:5bcc]) by smtp.gmail.com with ESMTPSA id p9sm990595wma.12.2020.10.15.19.40.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 15 Oct 2020 19:40:41 -0700 (PDT) From: Jann Horn To: Andrew Morton , linux-mm@kvack.org, Eric Biederman , Oleg Nesterov Cc: linux-kernel@vger.kernel.org, Will Deacon , Kees Cook , Ingo Molnar Subject: [RFC PATCH 6/6] mm: remove now-unused mmdrop_async() Date: Fri, 16 Oct 2020 04:40:19 +0200 Message-Id: <20201016024019.1882062-7-jannh@google.com> X-Mailer: git-send-email 2.29.0.rc1.297.gfa9743e501-goog In-Reply-To: <20201016024019.1882062-1-jannh@google.com> References: <20201016024019.1882062-1-jannh@google.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The preceding patches have removed all users of mmdrop_async(); get rid of it. Note that on MMU, we still need async_put_work because mmput_async() uses it, which in turn is used by binder's shrinker callback. We could claw back those 4 words per mm if we made mmput_async() depend on CONFIG_ANDROID_BINDER_IPC. Signed-off-by: Jann Horn --- include/linux/mm_types.h | 2 ++ kernel/fork.c | 16 ---------------- 2 files changed, 2 insertions(+), 16 deletions(-) diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 764d251966c7..8fde2068bde1 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -560,7 +560,9 @@ struct mm_struct { #ifdef CONFIG_HUGETLB_PAGE atomic_long_t hugetlb_usage; #endif +#ifdef CONFIG_MMU struct work_struct async_put_work; +#endif } __randomize_layout; /* diff --git a/kernel/fork.c b/kernel/fork.c index 4383bf055b40..c5f2ec544933 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -666,22 +666,6 @@ void __mmdrop(struct mm_struct *mm) } EXPORT_SYMBOL_GPL(__mmdrop); -static void mmdrop_async_fn(struct work_struct *work) -{ - struct mm_struct *mm; - - mm = container_of(work, struct mm_struct, async_put_work); - __mmdrop(mm); -} - -static void mmdrop_async(struct mm_struct *mm) -{ - if (unlikely(atomic_dec_and_test(&mm->mm_count))) { - INIT_WORK(&mm->async_put_work, mmdrop_async_fn); - schedule_work(&mm->async_put_work); - } -} - static inline void free_signal_struct(struct signal_struct *sig) { taskstats_tgid_free(sig); -- 2.29.0.rc1.297.gfa9743e501-goog