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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 211BCC2BD09 for ; Tue, 9 Jul 2024 06:21:31 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 94F6F6B0099; Tue, 9 Jul 2024 02:21:30 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 8D7296B009A; Tue, 9 Jul 2024 02:21:30 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 751F66B009B; Tue, 9 Jul 2024 02:21:30 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 4FE3C6B0099 for ; Tue, 9 Jul 2024 02:21:30 -0400 (EDT) Received: from smtpin29.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id F1C1A1416E6 for ; Tue, 9 Jul 2024 06:21:29 +0000 (UTC) X-FDA: 82319217498.29.0B945D5 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.11]) by imf19.hostedemail.com (Postfix) with ESMTP id CE5761A0016 for ; Tue, 9 Jul 2024 06:21:26 +0000 (UTC) Authentication-Results: imf19.hostedemail.com; dkim=pass header.d=intel.com header.s=Intel header.b=Ci09Fy4P; spf=pass (imf19.hostedemail.com: domain of ying.huang@intel.com designates 198.175.65.11 as permitted sender) smtp.mailfrom=ying.huang@intel.com; dmarc=pass (policy=none) header.from=intel.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1720506057; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=dnFkKON0n/5hBFtrU/kWy3P4RdahjZ7EDDqM2pye2Bo=; b=ccvLjmpCD+5fUq+FKbi7fJm47yApd1nRCX04P01NerQfjeUycUgz60VAjtsxH900BkTIV/ JjON3fM++BIVTCHQnADpQeB8w+a3VxcxXs0LllZztPnczxL1OvoAUWn4mRsjga4K1bXCTf 1DcwHCKnX0EhQGEZBaAIb/60J4a4T2c= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1720506057; a=rsa-sha256; cv=none; b=OTfYixwCuUocstGvXg/Zu3qHpHsbSY0VJLYLda+b8pXAp2+8eum0ktcOjH5/mMxb6DtR5L EfFXWfX0Dwdh5iyJLeqZiK9Ld/0TQeAj4fBgR+36XIGso8YEXS7FPUDk9dGcHiwq0SYlCi 6hYSh8g/EifKrZlox391UsEUoYUphVc= ARC-Authentication-Results: i=1; imf19.hostedemail.com; dkim=pass header.d=intel.com header.s=Intel header.b=Ci09Fy4P; spf=pass (imf19.hostedemail.com: domain of ying.huang@intel.com designates 198.175.65.11 as permitted sender) smtp.mailfrom=ying.huang@intel.com; dmarc=pass (policy=none) header.from=intel.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1720506087; x=1752042087; h=from:to:cc:subject:in-reply-to:references:date: message-id:mime-version; bh=GR3LjQQcsOfDijR4d6rjFBNH45bQPCCpzk+BKwaObsc=; b=Ci09Fy4P8O9QqdqNVUEmQoDB+zFQdTCrGZ+3j4IZEj5FZGbMm9+NrCIn ZryFPWBPa53Fg5VDC13WosuWveODxwy0sA04jYa2ib8lNqvf7gN94p0bj 0ttEAP7FFAoGMODcRzW/17/h7ENfLlMpyWgF4C+jLLgIjIdT4198ZynY3 pVXNMmaflt7xJxclHUc0ack1n1pLNbL07Kvq0JGHHSDrBpBb1CNTUxZt/ iQqDuSgYLJh+W8tjsrsSS+iVrWB0/56f2zV6EpwSKGynfyEldOT8FQCb4 2D54qy6smmfZiRlHwrAAIRAwcO5jojfSxIid5OKHZT4PItO1HyQ4/803f g==; X-CSE-ConnectionGUID: bDRW7i8tR9yMIqLTJK8CIQ== X-CSE-MsgGUID: ZjdDlU6CRI2toyuyMYHsTQ== X-IronPort-AV: E=McAfee;i="6700,10204,11127"; a="28339676" X-IronPort-AV: E=Sophos;i="6.09,194,1716274800"; d="scan'208";a="28339676" Received: from fmviesa005.fm.intel.com ([10.60.135.145]) by orvoesa103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Jul 2024 23:21:25 -0700 X-CSE-ConnectionGUID: v1qVtX4QRTGO3OSeC7LAcw== X-CSE-MsgGUID: LWlTtEBXQgy55AgPWu0piw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.09,194,1716274800"; d="scan'208";a="52146100" Received: from unknown (HELO yhuang6-desk2.ccr.corp.intel.com) ([10.238.208.55]) by fmviesa005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Jul 2024 23:21:21 -0700 From: "Huang, Ying" To: Tvrtko Ursulin Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-dev@igalia.com, Tvrtko Ursulin , Mel Gorman , Peter Zijlstra , Ingo Molnar , Rik van Riel , Johannes Weiner , "Matthew Wilcox (Oracle)" , Dave Hansen , Andi Kleen , Michal Hocko , David Rientjes , stable@vger.kernel.org Subject: Re: [PATCH v4] mm/numa_balancing: Teach mpol_to_str about the balancing mode In-Reply-To: <20240708075632.95857-1-tursulin@igalia.com> (Tvrtko Ursulin's message of "Mon, 8 Jul 2024 08:56:32 +0100") References: <20240708075632.95857-1-tursulin@igalia.com> Date: Tue, 09 Jul 2024 14:19:29 +0800 Message-ID: <87ttgzaxzi.fsf@yhuang6-desk2.ccr.corp.intel.com> User-Agent: Gnus/5.13 (Gnus v5.13) MIME-Version: 1.0 Content-Type: text/plain; charset=ascii X-Stat-Signature: fwf84ehd5rp7xg98znfhso71o34cxqox X-Rspamd-Queue-Id: CE5761A0016 X-Rspam-User: X-Rspamd-Server: rspam08 X-HE-Tag: 1720506086-216820 X-HE-Meta: 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 ZEuJGSeK 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 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: List-Subscribe: List-Unsubscribe: Tvrtko Ursulin writes: > From: Tvrtko Ursulin > > Since balancing mode was added in > bda420b98505 ("numa balancing: migrate on fault among multiple bound nodes"), > it was possible to set this mode but it wouldn't be shown in > /proc//numa_maps since there was no support for it in the > mpol_to_str() helper. > > Furthermore, because the balancing mode sets the MPOL_F_MORON flag, it > would be displayed as 'default' due a workaround introduced a few years > earlier in > 8790c71a18e5 ("mm/mempolicy.c: fix mempolicy printing in numa_maps"). > > To tidy this up we implement two changes: > > Replace the MPOL_F_MORON check by pointer comparison against the > preferred_node_policy array. By doing this we generalise the current > special casing and replace the incorrect 'default' with the correct > 'bind' for the mode. > > Secondly, we add a string representation and corresponding handling for > the MPOL_F_NUMA_BALANCING flag. > > With the two changes together we start showing the balancing flag when it > is set and therefore complete the fix. > > Representation format chosen is to separate multiple flags with vertical > bars, following what existed long time ago in kernel 2.6.25. But as > between then and now there wasn't a way to display multiple flags, this > patch does not change the format in practice. > > Some /proc//numa_maps output examples: > > 555559580000 bind=balancing:0-1,3 file=... > 555585800000 bind=balancing|static:0,2 file=... > 555635240000 prefer=relative:0 file= > > v2: > * Fully fix by introducing MPOL_F_KERNEL. > > v3: > * Abandoned the MPOL_F_KERNEL approach in favour of pointer comparisons. > * Removed lookup generalisation for easier backporting. > * Replaced commas as separator with vertical bars. > * Added a few more words about the string format in the commit message. > > v4: > * Use is_power_of_2. > * Use ARRAY_SIZE and update recommended buffer size for two flags. > > Signed-off-by: Tvrtko Ursulin > Fixes: bda420b98505 ("numa balancing: migrate on fault among multiple bound nodes") > References: 8790c71a18e5 ("mm/mempolicy.c: fix mempolicy printing in numa_maps") > Cc: Huang Ying > Cc: Mel Gorman > Cc: Peter Zijlstra > Cc: Ingo Molnar > Cc: Rik van Riel > Cc: Johannes Weiner > Cc: "Matthew Wilcox (Oracle)" > Cc: Dave Hansen > Cc: Andi Kleen > Cc: Michal Hocko > Cc: David Rientjes > Cc: # v5.12+ LGTM, Thanks! Reviewed-by: "Huang, Ying" > --- > mm/mempolicy.c | 18 ++++++++++++++---- > 1 file changed, 14 insertions(+), 4 deletions(-) > > diff --git a/mm/mempolicy.c b/mm/mempolicy.c > index aec756ae5637..a1bf9aa15c33 100644 > --- a/mm/mempolicy.c > +++ b/mm/mempolicy.c > @@ -3293,8 +3293,9 @@ int mpol_parse_str(char *str, struct mempolicy **mpol) > * @pol: pointer to mempolicy to be formatted > * > * Convert @pol into a string. If @buffer is too short, truncate the string. > - * Recommend a @maxlen of at least 32 for the longest mode, "interleave", the > - * longest flag, "relative", and to display at least a few node ids. > + * Recommend a @maxlen of at least 51 for the longest mode, "weighted > + * interleave", plus the longest flag flags, "relative|balancing", and to > + * display at least a few node ids. > */ > void mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol) > { > @@ -3303,7 +3304,10 @@ void mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol) > unsigned short mode = MPOL_DEFAULT; > unsigned short flags = 0; > > - if (pol && pol != &default_policy && !(pol->flags & MPOL_F_MORON)) { > + if (pol && > + pol != &default_policy && > + !(pol >= &preferred_node_policy[0] && > + pol <= &preferred_node_policy[ARRAY_SIZE(preferred_node_policy) - 1])) { > mode = pol->mode; > flags = pol->flags; > } > @@ -3331,12 +3335,18 @@ void mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol) > p += snprintf(p, buffer + maxlen - p, "="); > > /* > - * Currently, the only defined flags are mutually exclusive > + * Static and relative are mutually exclusive. > */ > if (flags & MPOL_F_STATIC_NODES) > p += snprintf(p, buffer + maxlen - p, "static"); > else if (flags & MPOL_F_RELATIVE_NODES) > p += snprintf(p, buffer + maxlen - p, "relative"); > + > + if (flags & MPOL_F_NUMA_BALANCING) { > + if (!is_power_of_2(flags & MPOL_MODE_FLAGS)) > + p += snprintf(p, buffer + maxlen - p, "|"); > + p += snprintf(p, buffer + maxlen - p, "balancing"); > + } > } > > if (!nodes_empty(nodes))