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 662D3C636D3 for ; Wed, 8 Feb 2023 22:23:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232427AbjBHWW7 (ORCPT ); Wed, 8 Feb 2023 17:22:59 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43962 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231906AbjBHWW5 (ORCPT ); Wed, 8 Feb 2023 17:22:57 -0500 Received: from mail-ed1-x52e.google.com (mail-ed1-x52e.google.com [IPv6:2a00:1450:4864:20::52e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3F760252BD; Wed, 8 Feb 2023 14:22:55 -0800 (PST) Received: by mail-ed1-x52e.google.com with SMTP id v13so419399eda.11; Wed, 08 Feb 2023 14:22:55 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=user-agent: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=fZrGQmCx7M8I538/uxkEeAKM0AP+vFbaSYYa4WZn5LM=; b=jwcQd+Vd/ZFK6qS29TU7c4K8ejZri73UlkOSeuG6KyaG3cdzdEPLRd5imadkMptaSL rA9J36JisG+j6S+lEgm+E73JrjikgizJ45abOgdNHePGCGIO+OnRn4ttUDHjHG7SrA9W BMx1ov5OnhkWaTlZBcbkCWICOj5KjSlaJethEd5nsR4huThx8+lzltQC+isnCKsdZtkc Sv2UOXCuKaRrqGCHuEnfGFKckVxu8lz8VqjPzLnzGEdWVzNQBWK2QlzEgIZYN0yEpjKJ T/HsCi9BF8Zft1NjnGmRW0DltXi+iZTEUrqciIT/IlaYozivvetbuZLJbzc2NooMKXAT hNKQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=user-agent: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=fZrGQmCx7M8I538/uxkEeAKM0AP+vFbaSYYa4WZn5LM=; b=o8FaXZQ8E0A8yHxmGQEieE3VTdyMHjEhRm/NtFYS0bxkKCOtltAQa8kwD9Mu3mWiae uuLNvGu2pqIrnCs1h4NMZt2POl1GJH+412AL8BMEgx7VH0ZjUzm7DOCLpNfddvt0Ts2+ RK+rE0ZybIMkE+b+a2wtzA+6F461Ye7zyAo2YdbFL36WCsUAPVt5c9nHk9aY4+KJCsil uRVO5psgjbq2c53s5kFpow6C4zjY5UoBzrdRMHDk6fAIV2KA9WLOdGYeLHxU3VGqSJyf FNYnJGcXWi22AOxaKcxA4wkmmir9ILqdR8kq1sRRhF1XV5gzPKij6x9Hw3+4/0yWjK3C /Dug== X-Gm-Message-State: AO0yUKWLGueUv4L1LnQXWVgJcy04eMJUi1A+dWnMqwuqNljEmly2X12v 5taVPQuSKN//C/2smAkC5mc= X-Google-Smtp-Source: AK7set9vfHaHysr9sj0VdzcRm6rskIqHOWhgkmctn4yaV1/jw9WLwRZnOAhGCD+UsYzR3gbXLFuLJA== X-Received: by 2002:a50:8a95:0:b0:4ab:1031:b60a with SMTP id j21-20020a508a95000000b004ab1031b60amr3492611edj.24.1675894973662; Wed, 08 Feb 2023 14:22:53 -0800 (PST) Received: from grain.localdomain ([5.18.251.97]) by smtp.gmail.com with ESMTPSA id y12-20020a056402270c00b0049668426aa6sm8426236edd.24.2023.02.08.14.22.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 08 Feb 2023 14:22:46 -0800 (PST) Received: by grain.localdomain (Postfix, from userid 1000) id 551D35A0020; Thu, 9 Feb 2023 01:22:45 +0300 (MSK) Date: Thu, 9 Feb 2023 01:22:45 +0300 From: Cyrill Gorcunov To: Muhammad Usama Anjum Cc: Peter Xu , David Hildenbrand , Andrew Morton , =?utf-8?B?TWljaGHFgiBNaXJvc8WCYXc=?= , Andrei Vagin , Danylo Mocherniuk , Paul Gofman , Alexander Viro , Shuah Khan , Christian Brauner , Yang Shi , Vlastimil Babka , "Liam R . Howlett" , Yun Zhou , Suren Baghdasaryan , Alex Sierra , Matthew Wilcox , Pasha Tatashin , Mike Rapoport , Nadav Amit , Axel Rasmussen , "Gustavo A . R . Silva" , Dan Williams , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, Greg KH , kernel@collabora.com Subject: Re: [PATCH v10 3/6] fs/proc/task_mmu: Implement IOCTL to get and/or the clear info about PTEs Message-ID: References: <20230202112915.867409-1-usama.anjum@collabora.com> <20230202112915.867409-4-usama.anjum@collabora.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230202112915.867409-4-usama.anjum@collabora.com> User-Agent: Mutt/2.2.9 (2022-11-12) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Feb 02, 2023 at 04:29:12PM +0500, Muhammad Usama Anjum wrote: ... Hi Muhammad! I'm really sorry for not commenting this code, just out of time and i fear cant look with precise care at least for some time, hopefully other CRIU guys pick it up. Anyway, here a few comment from a glance. > + > +static inline int pagemap_scan_output(bool wt, bool file, bool pres, bool swap, > + struct pagemap_scan_private *p, unsigned long addr, > + unsigned int len) > +{ This is a big function and usually it's a flag to not declare it as "inline" until there very serious reson to. > + unsigned long bitmap, cur = PAGEMAP_SCAN_BITMAP(wt, file, pres, swap); > + bool cpy = true; > + struct page_region *prev = &p->prev; > + > + if (HAS_NO_SPACE(p)) > + return -ENOSPC; > + > + if (p->max_pages && p->found_pages + len >= p->max_pages) > + len = p->max_pages - p->found_pages; > + if (!len) > + return -EINVAL; > + > + if (p->required_mask) > + cpy = ((p->required_mask & cur) == p->required_mask); > + if (cpy && p->anyof_mask) > + cpy = (p->anyof_mask & cur); > + if (cpy && p->excluded_mask) > + cpy = !(p->excluded_mask & cur); > + bitmap = cur & p->return_mask; > + if (cpy && bitmap) { You can exit early here simply if (!cpy || !bitmap) return 0; saving one tab for the code below. > + if ((prev->len) && (prev->bitmap == bitmap) && > + (prev->start + prev->len * PAGE_SIZE == addr)) { > + prev->len += len; > + p->found_pages += len; > + } else if (p->vec_index < p->vec_len) { > + if (prev->len) { > + memcpy(&p->vec[p->vec_index], prev, sizeof(struct page_region)); > + p->vec_index++; > + } > + prev->start = addr; > + prev->len = len; > + prev->bitmap = bitmap; > + p->found_pages += len; > + } else { > + return -ENOSPC; > + } > + } > + return 0; > +} > + > +static inline int export_prev_to_out(struct pagemap_scan_private *p, struct page_region __user *vec, > + unsigned long *vec_index) > +{ No need for inline either. > + struct page_region *prev = &p->prev; > + > + if (prev->len) { > + if (copy_to_user(&vec[*vec_index], prev, sizeof(struct page_region))) > + return -EFAULT; > + p->vec_index++; > + (*vec_index)++; > + prev->len = 0; > + } > + return 0; > +} > + > +static inline int pagemap_scan_pmd_entry(pmd_t *pmd, unsigned long start, > + unsigned long end, struct mm_walk *walk) > +{ Same, no need for inline. I've a few comments more in my mind will try to collect them tomorrow.