From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E25EC39F18F; Tue, 30 Jun 2026 07:28:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782804538; cv=none; b=CSS7voVaJhm5c8XrHBee56fSuizEIVhYlR/OwHkZ5ZJ5Yf0EFYs1VaR1+DB3jxbF//msoPqz6Ejtt/5h4jjHyxUpM9wYhbyigxxTW13Ugb2NDfwI5semx2T3JGmo20b1Fo0/SfSa1B0yO3Z5C3iJw2iwmUshAzjKV1X0DhKAM80= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782804538; c=relaxed/simple; bh=L5J1ZbkNIB3dmh3HiAbROGtIuFugcSaqe6hCF/3q9y0=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=hObIoP2S08WmNKreQdzFctVtLxX2sp82T/cNfDcaicIC3FA83yqY8q8S3Yu/W/YxZXyp+BdPAOVotzJC5WwM2tMEEOUkjWKgTpCzfy3QDf8HsjPcsDXJ8BfCoSzIs+cMjQ9xdXteszs2H5+odtSELI3wYJwsrsrZmsTzf1qe6Ck= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ZFn1H9jl; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ZFn1H9jl" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9B7FD1F00A3A; Tue, 30 Jun 2026 07:28:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1782804536; bh=e98YwUYuEo+jW47qdB3B72qgzQCPcBwfH7OsRH/ROPs=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=ZFn1H9jlfNmlH1zT6vtcHSnaiSbi+w7BvliNM5mVDFp+wwRol6gWi8l9XJFmyVO4V ZC1OzZrcylNAncXXABpRL0ALxO4K0qJwrvq4T8JaZ0mF0FJDHf/t1F0M0aTTptdnGV DekqlyscJV/ndvE/m1VWbF5ajxosTl6fQCgEMhkhHvYEtCbwwGiPwS22eCKS3vFCNn ds5NL/4mLjXeCEHrOH8GvdmXJ7DOAxUDaCZRo4Otx6TJe/MQV3VzXtdtDd58ZYvjV7 peUS7KnRBrPkttuQkrZbMkvM+YX+uFCx6hhhtWH4ZAt9u8l6FTINtva91gsMByKy6v YiKx4MywKrGtw== Message-ID: Date: Tue, 30 Jun 2026 09:28:50 +0200 Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 2/7] mm/page_owner: add MR_NEVER to enum migrate_reason and use it for last_migrate_reason Content-Language: en-US To: Ye Liu , Andrew Morton , David Hildenbrand , Steven Rostedt , Masami Hiramatsu Cc: Zi Yan , Matthew Brost , Joshua Hahn , Rakie Kim , Byungchul Park , Gregory Price , Ying Huang , Alistair Popple , Mathieu Desnoyers , Suren Baghdasaryan , Michal Hocko , Brendan Jackman , Johannes Weiner , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org References: <20260630015331.147174-1-ye.liu@linux.dev> <20260630015331.147174-3-ye.liu@linux.dev> From: "Vlastimil Babka (SUSE)" Autocrypt: addr=vbabka@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 6/30/26 03:53, Ye Liu wrote: > The last_migrate_reason field uses -1 as a sentinel value to mean "no > migration has happened". Replace the four bare -1 occurrences by > adding a proper MR_NEVER member to enum migrate_reason, defining a > corresponding "never_migrated" string in the MIGRATE_REASON trace > macro, and removing the local MIGRATE_REASON_NONE define. > > No functional change. > > Signed-off-by: Ye Liu Reviewed-by: Vlastimil Babka (SUSE) > --- > include/linux/migrate_mode.h | 1 + > include/trace/events/migrate.h | 3 ++- > mm/page_owner.c | 8 ++++---- > 3 files changed, 7 insertions(+), 5 deletions(-) > > diff --git a/include/linux/migrate_mode.h b/include/linux/migrate_mode.h > index 265c4328b36a..05102d4d2490 100644 > --- a/include/linux/migrate_mode.h > +++ b/include/linux/migrate_mode.h > @@ -25,6 +25,7 @@ enum migrate_reason { > MR_LONGTERM_PIN, > MR_DEMOTION, > MR_DAMON, > + MR_NEVER, /* page has never been migrated */ > MR_TYPES > }; > > diff --git a/include/trace/events/migrate.h b/include/trace/events/migrate.h > index cd01dd7b3640..11bc0aa14c7e 100644 > --- a/include/trace/events/migrate.h > +++ b/include/trace/events/migrate.h > @@ -23,7 +23,8 @@ > EM( MR_CONTIG_RANGE, "contig_range") \ > EM( MR_LONGTERM_PIN, "longterm_pin") \ > EM( MR_DEMOTION, "demotion") \ > - EMe(MR_DAMON, "damon") > + EM( MR_DAMON, "damon") \ > + EMe(MR_NEVER, "never_migrated") > > /* > * First define the enums in the above macros to be exported to userspace > diff --git a/mm/page_owner.c b/mm/page_owner.c > index 342549891a8d..c2f43ab860eb 100644 > --- a/mm/page_owner.c > +++ b/mm/page_owner.c > @@ -339,7 +339,7 @@ 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, MR_NEVER, > ts_nsec, current->pid, current->tgid, > current->comm); > inc_stack_record_count(handle, gfp_mask, 1 << order); > @@ -596,7 +596,7 @@ 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 != MR_NEVER) { > 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 +667,7 @@ 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 != MR_NEVER) > 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 +826,7 @@ 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, > + MR_NEVER, local_clock(), current->pid, > current->tgid, current->comm); > count++; > ext_put_continue: