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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 CAF38C433DB for ; Mon, 1 Feb 2021 13:27:45 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 2740464E8F for ; Mon, 1 Feb 2021 13:27:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2740464E8F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 95A356B0075; Mon, 1 Feb 2021 08:27:44 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 932866B0078; Mon, 1 Feb 2021 08:27:44 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7FA196B007B; Mon, 1 Feb 2021 08:27:44 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0120.hostedemail.com [216.40.44.120]) by kanga.kvack.org (Postfix) with ESMTP id 6A25B6B0075 for ; Mon, 1 Feb 2021 08:27:44 -0500 (EST) Received: from smtpin06.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 1F686362C for ; Mon, 1 Feb 2021 13:27:44 +0000 (UTC) X-FDA: 77769776448.06.sun27_3103bb5275c2 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin06.hostedemail.com (Postfix) with ESMTP id E93001003F335 for ; Mon, 1 Feb 2021 13:27:43 +0000 (UTC) X-HE-Tag: sun27_3103bb5275c2 X-Filterd-Recvd-Size: 7993 Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by imf31.hostedemail.com (Postfix) with ESMTP for ; Mon, 1 Feb 2021 13:27:42 +0000 (UTC) IronPort-SDR: dIG0V/YdI34oXKPXfMJyaWZqLYWIqw1r5s/RQpxmBFUPckJkAEkMmQGiGT6qSLoIz/hXK8padq U68CWL7/3r3Q== X-IronPort-AV: E=McAfee;i="6000,8403,9881"; a="160448386" X-IronPort-AV: E=Sophos;i="5.79,392,1602572400"; d="scan'208";a="160448386" Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Feb 2021 05:27:40 -0800 IronPort-SDR: NFfJUo0fRHuqD7yUs1A6erkBL7AjmwTAUEbZgtP2Cunlf56nxROWnaMVa6i1cwUN/hwEVDi/pH Il6+b4hO5GWg== X-IronPort-AV: E=Sophos;i="5.79,392,1602572400"; d="scan'208";a="405692679" Received: from smile.fi.intel.com (HELO smile) ([10.237.68.40]) by fmsmga004-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Feb 2021 05:27:37 -0800 Received: from andy by smile with local (Exim 4.94) (envelope-from ) id 1l6ZEr-0018kN-CS; Mon, 01 Feb 2021 15:27:33 +0200 Date: Mon, 1 Feb 2021 15:27:33 +0200 From: Andy Shevchenko To: Yafang Shao Cc: david@redhat.com, vbabka@suse.cz, linmiaohe@huawei.com, cl@linux.com, penberg@kernel.org, rientjes@google.com, iamjoonsoo.kim@lge.com, akpm@linux-foundation.org, pmladek@suse.com, rostedt@goodmis.org, sergey.senozhatsky@gmail.com, linux@rasmusvillemoes.dk, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Joe Perches Subject: Re: [PATCH v2 3/3] vsprintf: dump full information of page flags in pGp Message-ID: References: <20210201115610.87808-1-laoar.shao@gmail.com> <20210201115610.87808-4-laoar.shao@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210201115610.87808-4-laoar.shao@gmail.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Mon, Feb 01, 2021 at 07:56:10PM +0800, Yafang Shao wrote: > Currently the pGp only shows the names of page flags, rather than > the full information including section, node, zone, last cpupid and > kasan tag. While it is not easy to parse these information manually > because there're so many flavors. Let's interpret them in pGp as well. > > - Before the patch, > [ 6343.396602] Slab 0x000000004382e02b objects=33 used=3 fp=0x000000009ae06ffc flags=0x17ffffc0010200(slab|head) > > - After the patch, > [ 6871.296131] Slab 0x00000000c0e19a37 objects=33 used=3 fp=0x00000000c4902159 flags=0x17ffffc0010200(Node 0,Zone 2,Lastcpupid 0x1fffff,slab|head) > > The Documentation and test cases are also updated. Thanks for an update, my comments below. ... > - %pGp referenced|uptodate|lru|active|private > + %pGp Node 0,Zone 2,referenced|uptodate|lru|active|private Since of the nature of printf() buffer, I wonder if these should be at the end. I.o.w. the question is is the added material more important to user to see than the existed one? ... > +static void __init > +page_flags_test(int section, int node, int zone, int last_cpupid, > + int kasan_tag, int flags, const char *name, char *cmp_buf) > +{ > + unsigned long page_flags = 0; > + unsigned long size = 0; > + > +#ifdef SECTION_IN_PAGE_FLAGS > + page_flags |= (sec & SECTIONS_MASK) << SECTIONS_PGSHIFT; > + snprintf(cmp_buf, BUF_SIZE, "Section %#x,", sec); I would keep it in the same form as latter ones, i.e. snprintf(cmp_buf + size, BUF_SIZE - size, "Section %#x,", sec); In this case it will be easier if at some point we might need to reshuffle. > + size = strlen(cmp_buf); > +#endif > + > + page_flags |= (node & NODES_MASK) << NODES_PGSHIFT; > + snprintf(cmp_buf + size, BUF_SIZE - size, "Node %d", node); > + size = strlen(cmp_buf); > + > + page_flags |= (zone & ZONES_MASK) << ZONES_PGSHIFT; > + snprintf(cmp_buf + size, BUF_SIZE - size, ",Zone %d", zone); > + size = strlen(cmp_buf); > + > +#ifndef LAST_CPUPID_NOT_IN_PAGE_FLAGS > + page_flags |= (last_cpupid & LAST_CPUPID_MASK) << LAST_CPUPID_PGSHIFT; > + snprintf(cmp_buf + size, BUF_SIZE - size, ",Lastcpupid %#x", last_cpupid); > + size = strlen(cmp_buf); > +#endif > + > +#if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS) > + page_flags |= (tag & KASAN_TAG_MASK) << KASAN_TAG_PGSHIFT; > + snprintf(cmp_buf + size, BUF_SIZE - size, ",Kasantag %#x", tag); > + size = strlen(cmp_buf); > +#endif > + > + test(cmp_buf, "%pGp", &page_flags); > + > + if (flags) { If below will be always for flags set, I would rewrite this condition as if (!flags) return; but it's up to you. > + page_flags |= flags; > + snprintf(cmp_buf + size, BUF_SIZE - size, ",%s", name); > + test(cmp_buf, "%pGp", &page_flags); > + } > +} ... > - flags = 0; > - flags |= 1UL << PG_uptodate | 1UL << PG_dirty | 1UL << PG_lru > - | 1UL << PG_active | 1UL << PG_swapbacked; I would leave this untouched and reuse below... > + cmp_buffer = kmalloc(BUF_SIZE, GFP_KERNEL); > + if (!cmp_buffer) > + return; ...as > + page_flags_test(0, 0, 0, 0, 0, 0, NULL, cmp_buffer); flags = 0; page_flags_test(0, 0, 0, 0, 0, flags, NULL, cmp_buffer); > + page_flags_test(1, 1, 1, 0x1ffff, 1, > + (1UL << PG_uptodate | 1UL << PG_dirty | 1UL << PG_lru > + | 1UL << PG_active | 1UL << PG_swapbacked), > + "uptodate|dirty|lru|active|swapbacked", > + cmp_buffer); flags |= 1UL << PG_uptodate | 1UL << PG_dirty | 1UL << PG_lru | 1UL << PG_active | 1UL << PG_swapbacked; page_flags_test(1, 1, 1, 0x1ffff, 1, flags, "uptodate|dirty|lru|active|swapbacked", cmp_buffer); ... > +static const struct page_flags_layout pfl[] = { > + {SECTIONS_WIDTH, SECTIONS_PGSHIFT, SECTIONS_MASK, > + &default_dec_spec, "Section "}, > + {NODES_WIDTH, NODES_PGSHIFT, NODES_MASK, > + &default_dec_spec, "Node "}, > + {ZONES_WIDTH, ZONES_PGSHIFT, ZONES_MASK, > + &default_dec_spec, "Zone "}, > + {LAST_CPUPID_WIDTH, LAST_CPUPID_PGSHIFT, LAST_CPUPID_MASK, > + &default_flag_spec, "Lastcpupid "}, > + {KASAN_TAG_WIDTH, KASAN_TAG_PGSHIFT, KASAN_TAG_MASK, > + &default_flag_spec, "Kasantag "}, > +}; Please add trailing space only once where it's needed (below in the code). ... > +static > +char *format_page_flags(char *buf, char *end, unsigned long page_flags) > +{ > + unsigned long flags = page_flags & ((1UL << NR_PAGEFLAGS) - 1); > + int size = ARRAY_SIZE(pfl); > + bool separator = false; > + int i; > + > + for (i = 0; i < size; i++) { > + if (pfl[i].width == 0) > + continue; > + > + if (separator) { > + if (buf < end) > + *buf = ','; > + buf++; > + } > + > + One blank line is enough. > + buf = string(buf, end, pfl[i].name, *pfl[i].spec); > + > + buf = number(buf, end, (page_flags >> pfl[i].shift) & pfl[i].mask, > + *pfl[i].spec); > + separator = true; > + } > + > + if (flags) { > + if (buf < end) > + *buf = ','; > + buf++; > + } I think you may optimize above to avoid using the separator variable. DECLARE_BITMAP(mask, ARRAY_SIZE(pfl)); unsigned long flags; unsigned long last; for (i = 0; i < ARRAY_SIZE(pfl); i++) __assign_bit(mask, pfl[i].width); last = find_last_bit(mask, ARRAY_SIZE(pfl)); for_each_set_bit(i, mask, ARRAY_SIZE(pfl)) { flags = (page_flags >> pfl[i].shift) & pfl[i].mask; /* Format: Flag Name + ' ' (space) + Number + ',' (separator) */ buf = string(buf, end, pfl[i].name, *pfl[i].spec); if (buf < end) *buf = ' '; buf++; buf = number(buf, end, flags, *pfl[i].spec); /* No separator for the last entry */ if ((page_flags & (BIT(NR_PAGEFLAGS) - 1)) || (i != last)) { if (buf < end) *buf = ','; buf++; } } > + return buf; > +} -- With Best Regards, Andy Shevchenko