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]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 4538CCDE008 for ; Fri, 26 Jun 2026 02:46:14 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 2AD956B00B7; Thu, 25 Jun 2026 22:46:13 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 2844F6B00B8; Thu, 25 Jun 2026 22:46:13 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 173B16B00B9; Thu, 25 Jun 2026 22:46:13 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id E75A76B00B7 for ; Thu, 25 Jun 2026 22:46:12 -0400 (EDT) Received: from smtpin01.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 71C04C1A97 for ; Fri, 26 Jun 2026 02:46:12 +0000 (UTC) X-FDA: 84920524584.01.2E14CC5 Received: from out-184.mta0.migadu.com (out-184.mta0.migadu.com [91.218.175.184]) by imf02.hostedemail.com (Postfix) with ESMTP id D50BF80002 for ; Fri, 26 Jun 2026 02:46:10 +0000 (UTC) Authentication-Results: imf02.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=MuNcYjPT; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf02.hostedemail.com: domain of ye.liu@linux.dev designates 91.218.175.184 as permitted sender) smtp.mailfrom=ye.liu@linux.dev ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1782441970; b=xMz6a7wDUC79wum40rpuwALerhQVBY/GrcBTJrXm758vX1qKc8zg1EMG1mePJ5so2WQKHi ymAOveIIkfzslU+FTqPQxn6b6NZNvb2sO6FjjnsnWMmgyJlvHN5huwSmDPw8WSDdhN99Sw uH7SpYqVl0lbzyRgKdhRpjT9SKfji00= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1782441970; 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-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=0dUyOBnUAmeOV/VpmEyx25JanzSfW2aamrhE6D4NgAk=; b=khY5MKpalDGcX+SwzCMJMAtRk5xDpMa6y6L/8SzjBztSJkLn8Bmg2+ZXRs20X02xlZyM/8 kcjw48Ap6sAggn/R702MIxEDO7GFb8ePcKMsA6RaQsKjmnHfTlmF2KIWWUnyIpGXFce2NF cMtjZJRNCGyHIeR+yxhNPAK81VqWg+4= ARC-Authentication-Results: i=1; imf02.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=MuNcYjPT; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf02.hostedemail.com: domain of ye.liu@linux.dev designates 91.218.175.184 as permitted sender) smtp.mailfrom=ye.liu@linux.dev X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1782441969; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=0dUyOBnUAmeOV/VpmEyx25JanzSfW2aamrhE6D4NgAk=; b=MuNcYjPTB0GgnR9RtSNJrEf2vkrdCPnkRQcySpNJ/NWqNCOdi4qwh0Fm04fcx7tDpdGN7J lvSCzFstf9W0WUx/4VNp4L8WrcXXf4ZGDQBaoyNryyQyqjLQJtBh3Fx15T0HccwW/PYDmu PlOSaHpdxnX2HHWR4b0PrXzZqSgNPE0= From: Ye Liu To: Andrew Morton , Vlastimil Babka Cc: Ye Liu , Suren Baghdasaryan , Michal Hocko , Brendan Jackman , Johannes Weiner , Zi Yan , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 2/6] mm/page_owner: use MIGRATE_REASON_NONE instead of -1 for last_migrate_reason Date: Fri, 26 Jun 2026 10:45:41 +0800 Message-ID: <20260626024550.25677-3-ye.liu@linux.dev> In-Reply-To: <20260626024550.25677-1-ye.liu@linux.dev> References: <20260626024550.25677-1-ye.liu@linux.dev> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-Rspam-User: X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: D50BF80002 X-Stat-Signature: 95tiap9t59z7wzsbyy87hh763iyagg9s X-HE-Tag: 1782441970-723848 X-HE-Meta: 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 ajHSXzKa A05HOxFDVOD3j9BN0LiKY2QSHEzZiHjrE7R6+dKibtJxi4WaDYcWq5OKE3rZ2peuvtWEP71/amYygv7VmQuTV8kpgICPG+sJzrZX3JrjxuzetiAxI66JryJl2HIoHBRxm14CSSfs64LfxxU5xCMWeP+KfU018lpEqy5vaqfcb1xZXM4IRZfAQnhKVaVoWzdWdMXLmzOB7Bmwt42PJV2LqRRFsnuamxTutrk/G9LVsIdHVaBuNowkk8stQDg== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: The last_migrate_reason field uses -1 as a sentinel value to mean "no migration has happened". Replace the four bare -1 occurrences with a local MIGRATE_REASON_NONE define so the intent is explicit and the magic number is eliminated. No functional change. Signed-off-by: Ye Liu --- mm/page_owner.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/mm/page_owner.c b/mm/page_owner.c index 342549891a8d..ebafa9d7ff07 100644 --- a/mm/page_owner.c +++ b/mm/page_owner.c @@ -21,6 +21,13 @@ */ #define PAGE_OWNER_STACK_DEPTH (16) +/* + * Used to indicate that a page has never been migrated, as the valid + * migrate_reason values are non-negative enum members (MR_* in + * include/linux/migrate_mode.h). + */ +#define MIGRATE_REASON_NONE (-1) + struct page_owner { unsigned short order; short last_migrate_reason; @@ -339,7 +346,7 @@ noinline void __set_page_owner(struct page *page, unsigned short order, depot_stack_handle_t handle; handle = save_stack(gfp_mask); - __update_page_owner_handle(page, handle, order, gfp_mask, -1, + __update_page_owner_handle(page, handle, order, gfp_mask, MIGRATE_REASON_NONE, ts_nsec, current->pid, current->tgid, current->comm); inc_stack_record_count(handle, gfp_mask, 1 << order); @@ -596,7 +603,7 @@ print_page_owner(char __user *buf, size_t count, unsigned long pfn, if (ret >= count) goto err; - if (page_owner->last_migrate_reason != -1) { + if (page_owner->last_migrate_reason != MIGRATE_REASON_NONE) { ret += scnprintf(kbuf + ret, count - ret, "Page has been migrated, last migrate reason: %s\n", migrate_reason_names[page_owner->last_migrate_reason]); @@ -667,7 +674,7 @@ void __dump_page_owner(const struct page *page) stack_depot_print(handle); } - if (page_owner->last_migrate_reason != -1) + if (page_owner->last_migrate_reason != MIGRATE_REASON_NONE) pr_alert("page has been migrated, last migrate reason: %s\n", migrate_reason_names[page_owner->last_migrate_reason]); page_ext_put(page_ext); @@ -826,7 +833,7 @@ static void init_pages_in_zone(struct zone *zone) /* Found early allocated page */ __update_page_owner_handle(page, early_handle, 0, 0, - -1, local_clock(), current->pid, + MIGRATE_REASON_NONE, local_clock(), current->pid, current->tgid, current->comm); count++; ext_put_continue: -- 2.43.0