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=-11.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 5D3EAC43467 for ; Fri, 16 Oct 2020 10:41:09 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id AAE9420872 for ; Fri, 16 Oct 2020 10:41:08 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AAE9420872 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.cz Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id AE231940007; Fri, 16 Oct 2020 06:41:07 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A9199900002; Fri, 16 Oct 2020 06:41:07 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 97F92940007; Fri, 16 Oct 2020 06:41:07 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 6D843900002 for ; Fri, 16 Oct 2020 06:41:07 -0400 (EDT) Received: from smtpin26.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id EB98D362D for ; Fri, 16 Oct 2020 10:41:06 +0000 (UTC) X-FDA: 77377446132.26.fear78_4b069602721c Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin26.hostedemail.com (Postfix) with ESMTP id C3E7F1804B661 for ; Fri, 16 Oct 2020 10:41:06 +0000 (UTC) X-HE-Tag: fear78_4b069602721c X-Filterd-Recvd-Size: 4884 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf02.hostedemail.com (Postfix) with ESMTP for ; Fri, 16 Oct 2020 10:41:06 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id B892DAB5C; Fri, 16 Oct 2020 10:41:04 +0000 (UTC) To: Zhenhua Huang , akpm@linux-foundation.org Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org References: <1602839640-13125-1-git-send-email-zhenhuah@codeaurora.org> From: Vlastimil Babka Subject: Re: [PATCH] mm: fix page_owner initializing issue for arm32 Message-ID: <1a1a80b8-2ce4-9346-f333-68f3bb8b25c0@suse.cz> Date: Fri, 16 Oct 2020 12:41:04 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.3.2 MIME-Version: 1.0 In-Reply-To: <1602839640-13125-1-git-send-email-zhenhuah@codeaurora.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: quoted-printable 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 10/16/20 11:14 AM, Zhenhua Huang wrote: > Page owner of pages used by page owner itself used is missing on arm32 = targets. > The reason is dummy_handle and failure_handle is not initialized correc= tly. > Buddy allocator is used to initialize these two handles. However, buddy > allocator is not ready when page owner calls it. This change fixed that= by > initializing page owner after buddy initialization. >=20 > The working flow before and after this change are: > original logic: > 1. allocated memory for page_ext(using memblock). > 2. invoke the init callback of page_ext_ops like > page_owner(using buddy allocator). > 3. initialize buddy. >=20 > after this change: > 1. allocated memory for page_ext(using memblock). > 2. initialize buddy. > 3. invoke the init callback of page_ext_ops like > page_owner(using buddy allocator). >=20 > with the change, failure/dummy_handle can get its correct value and > page owner output for example has the one for page owner itself: > Page allocated via order 2, mask 0x6202c0(GFP_USER|__GFP_NOWARN), pid 1= 006, ts > 67278156558 ns > PFN 543776 type Unmovable Block 531 type Unmovable Flags 0x0() > init_page_owner+0x28/0x2f8 > invoke_init_callbacks_flatmem+0x24/0x34 > start_kernel+0x33c/0x5d8 > (null) register_dummy_stack should also appear in the above. Either one too many= is=20 skipped in arm32 stack saving, or the noinline is not honoured. Could be=20 investigated separately. >=20 > Signed-off-by: Zhenhua Huang This should be safe, as the sparse variant page_ext_init() runs even late= r, so: Acked-by: Vlastimil Babka Nit below: > --- > include/linux/page_ext.h | 8 ++++++++ > init/main.c | 2 ++ > mm/page_ext.c | 8 +++++++- > 3 files changed, 17 insertions(+), 1 deletion(-) >=20 > diff --git a/include/linux/page_ext.h b/include/linux/page_ext.h > index cfce186..aff81ba 100644 > --- a/include/linux/page_ext.h > +++ b/include/linux/page_ext.h > @@ -44,8 +44,12 @@ static inline void page_ext_init_flatmem(void) > { > } > extern void page_ext_init(void); > +static inline void page_ext_init_flatmem_late(void) > +{ > +} > #else > extern void page_ext_init_flatmem(void); > +extern void page_ext_init_flatmem_late(void); > static inline void page_ext_init(void) > { > } > @@ -76,6 +80,10 @@ static inline void page_ext_init(void) > { > } > =20 > +static inline void page_ext_init_flatmem_late(void) > +{ > +} > + > static inline void page_ext_init_flatmem(void) > { > } > diff --git a/init/main.c b/init/main.c > index 130376e..b34c475 100644 > --- a/init/main.c > +++ b/init/main.c > @@ -818,6 +818,8 @@ static void __init mm_init(void) > init_debug_pagealloc(); > report_meminit(); > mem_init(); > + /* page_owner must be initialized after buddy is ready */ > + page_ext_init_flatmem_late(); > kmem_cache_init(); > kmemleak_init(); > pgtable_init(); > diff --git a/mm/page_ext.c b/mm/page_ext.c > index a3616f7..373f7a1 100644 > --- a/mm/page_ext.c > +++ b/mm/page_ext.c > @@ -99,6 +99,13 @@ static void __init invoke_init_callbacks(void) > } > } > =20 > +#if !defined(CONFIG_SPARSEMEM) #ifndef is more common if you don't need boolean ops on multiple configs > +void __init page_ext_init_flatmem_late(void) > +{ > + invoke_init_callbacks(); > +} > +#endif > + > static inline struct page_ext *get_entry(void *base, unsigned long in= dex) > { > return base + page_ext_size * index; > @@ -177,7 +184,6 @@ void __init page_ext_init_flatmem(void) > goto fail; > } > pr_info("allocated %ld bytes of page_ext\n", total_usage); > - invoke_init_callbacks(); > return; > =20 > fail: >=20