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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0F0A6C10DC1 for ; Mon, 4 Dec 2023 14:46:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345969AbjLDOqn (ORCPT ); Mon, 4 Dec 2023 09:46:43 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45954 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236034AbjLDOqZ (ORCPT ); Mon, 4 Dec 2023 09:46:25 -0500 Received: from mail-pl1-x634.google.com (mail-pl1-x634.google.com [IPv6:2607:f8b0:4864:20::634]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6FA2A1715 for ; Mon, 4 Dec 2023 06:45:46 -0800 (PST) Received: by mail-pl1-x634.google.com with SMTP id d9443c01a7336-1d0b2752dc6so5409715ad.3 for ; Mon, 04 Dec 2023 06:45:46 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1701701146; x=1702305946; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=xUpQLJnz6spGXdfudxXpxtAg2n16wZAxITJJuVJ6Obk=; b=0Rm75Cgsw/4P3YPiGJAbStwJNfEmwLnNbshQ63C732oublHCZC8slK7yE9fKiZbLo8 Rvhcy+07EJyG3tFlw9VD/80xSp5lYZyKzrKcrzF+R5tPCAtadUWY76LN3q/dwYHSmG01 8gF90WHn6Fmvyu4j2ruRoaRwiUr9POrRxWjOJOdeVd8UusmJzQswgpF5f4mo4u1JVvAA 2Zql6qymcCAh05BCc3Np+xCRnLLVGxnTYdQq64p3ppDMj5jTDHHfQGy4LrYAjcPSpEoS yrO8R/8Ac0/QB7sBZ6sOBqSWZg3D2lCBnpi8WB/UJ25DDu7NWaGA/NV3V2V0nN3kMccA DRtg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1701701146; x=1702305946; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=xUpQLJnz6spGXdfudxXpxtAg2n16wZAxITJJuVJ6Obk=; b=T/i/xXKRZqcMNo0fCbzLynS6ntIQXUm7P78MCDPnDrstTRHgGcaPVsO0napOjpNiuV RTai92cqJXBLH/C3H1pf1sz+JY7soX0GQPvu7/tUfBNz+wIE6txHgZxQqVdUHpiw7Ou+ XYeNtTiCOT0iVlaD77OTuufrL9SA9PiTqiLYvikljicRD84nTc9SVpFmVmGwlLjOnjBh OVr5bndLgRtBt9gxS2EkICPpTLaXiPPVbeAcQC13fQQGVpRHJN0UwHxyiwSrzOYulyXe dDlHv/NHz9c3Qvds2oZR4Bl4OYAZXx5LnaUrg32WgiwEDs0HQcn5OFB8kWyU9od/pkQ4 3UDA== X-Gm-Message-State: AOJu0Yy5+Y7HZVy1QmtmPYpx8Ojgc8/e6DFnVa+ZAwGMjpxGMZTS0nPp YzNE23wSu/GKu98mjxAbpvKmrQ== X-Google-Smtp-Source: AGHT+IFMhw39D7FsQnfjuN1rEiP/cQ7PQGGaO8SsRg4qsMyilMpHPeXlZ/v+BEqSMHezhM6bTol4OA== X-Received: by 2002:a17:902:c405:b0:1d0:6ffd:9e09 with SMTP id k5-20020a170902c40500b001d06ffd9e09mr5259772plk.91.1701701145699; Mon, 04 Dec 2023 06:45:45 -0800 (PST) Received: from google.com (170.102.105.34.bc.googleusercontent.com. [34.105.102.170]) by smtp.gmail.com with ESMTPSA id 13-20020a170902c20d00b001d087f68ef8sm3152842pll.37.2023.12.04.06.45.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 04 Dec 2023 06:45:45 -0800 (PST) Date: Mon, 4 Dec 2023 14:45:42 +0000 From: Carlos Llamas To: Alice Ryhl Cc: arve@android.com, brauner@kernel.org, gregkh@linuxfoundation.org, joel@joelfernandes.org, kernel-team@android.com, linux-kernel@vger.kernel.org, maco@android.com, surenb@google.com, tkjos@android.com Subject: Re: [PATCH v2 27/28] binder: reverse locking order in shrinker callback Message-ID: References: <20231201172212.1813387-28-cmllamas@google.com> <20231204115743.43597-1-aliceryhl@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20231204115743.43597-1-aliceryhl@google.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 04, 2023 at 11:57:42AM +0000, 'Alice Ryhl' via kernel-team wrote: > > + trace_binder_unmap_kernel_start(alloc, index); > > + > > + page_to_free = page->page_ptr; > > + page->page_ptr = NULL; > > + > > + trace_binder_unmap_kernel_end(alloc, index); > > What are these trace calls used for? Previously they wrapped the call to > __free_page, and happened after the `trace_binder_unmap_user_*` calls. > It also used to wrap an unmap_kernel_range() call, which explains the naming of the tracepoint I suppose. It looked like this: trace_binder_unmap_kernel_start(alloc, index); unmap_kernel_range(page_addr, PAGE_SIZE); __free_page(page->page_ptr); page->page_ptr = NULL; trace_binder_unmap_kernel_end(alloc, index); My thinking was that we care more about the page->page_ptr clearing but it sounds like we could just drop the tracepoint, we no longer have a kernel mapped area. -- Carlos Llamas