From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; dkim=none Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 78170122; Tue, 21 Nov 2023 03:54:43 -0800 (PST) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id BBD48FEC; Tue, 21 Nov 2023 03:55:29 -0800 (PST) Received: from arm.com (e121798.cambridge.arm.com [10.1.197.44]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id DD1103F7A6; Tue, 21 Nov 2023 03:54:38 -0800 (PST) Date: Tue, 21 Nov 2023 11:54:36 +0000 From: Alexandru Elisei To: Peter Collingbourne Cc: catalin.marinas@arm.com, will@kernel.org, oliver.upton@linux.dev, maz@kernel.org, james.morse@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, arnd@arndb.de, akpm@linux-foundation.org, mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, mhiramat@kernel.org, rppt@kernel.org, hughd@google.com, steven.price@arm.com, anshuman.khandual@arm.com, vincenzo.frascino@arm.com, david@redhat.com, eugenis@google.com, kcc@google.com, hyesoo.yu@samsung.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kvmarm@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org Subject: Re: [PATCH RFC 20/37] mm: compaction: Reserve metadata storage in compaction_alloc() Message-ID: References: <20230823131350.114942-1-alexandru.elisei@arm.com> <20230823131350.114942-21-alexandru.elisei@arm.com> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Hi Peter, On Mon, Nov 20, 2023 at 08:49:32PM -0800, Peter Collingbourne wrote: > Hi Alexandru, > > On Wed, Aug 23, 2023 at 6:16 AM Alexandru Elisei > wrote: > > > > If the source page being migrated has metadata associated with it, make > > sure to reserve the metadata storage when choosing a suitable destination > > page from the free list. > > > > Signed-off-by: Alexandru Elisei > > --- > > mm/compaction.c | 9 +++++++++ > > mm/internal.h | 1 + > > 2 files changed, 10 insertions(+) > > > > diff --git a/mm/compaction.c b/mm/compaction.c > > index cc0139fa0cb0..af2ee3085623 100644 > > --- a/mm/compaction.c > > +++ b/mm/compaction.c > > @@ -570,6 +570,7 @@ static unsigned long isolate_freepages_block(struct compact_control *cc, > > bool locked = false; > > unsigned long blockpfn = *start_pfn; > > unsigned int order; > > + int ret; > > > > /* Strict mode is for isolation, speed is secondary */ > > if (strict) > > @@ -626,6 +627,11 @@ static unsigned long isolate_freepages_block(struct compact_control *cc, > > > > /* Found a free page, will break it into order-0 pages */ > > order = buddy_order(page); > > + if (metadata_storage_enabled() && cc->reserve_metadata) { > > + ret = reserve_metadata_storage(page, order, cc->gfp_mask); > > At this point the zone lock is held and preemption is disabled, which > makes it invalid to call reserve_metadata_storage. You are correct, I missed that. I dropped reserving tag storage during compaction in the next iteration, so fortunately I unintentionally fixed it. Thanks, Alex > > Peter > > > + if (ret) > > + goto isolate_fail; > > + } > > isolated = __isolate_free_page(page, order); > > if (!isolated) > > break; > > @@ -1757,6 +1763,9 @@ static struct folio *compaction_alloc(struct folio *src, unsigned long data) > > struct compact_control *cc = (struct compact_control *)data; > > struct folio *dst; > > > > + if (metadata_storage_enabled()) > > + cc->reserve_metadata = folio_has_metadata(src); > > + > > if (list_empty(&cc->freepages)) { > > isolate_freepages(cc); > > > > diff --git a/mm/internal.h b/mm/internal.h > > index d28ac0085f61..046cc264bfbe 100644 > > --- a/mm/internal.h > > +++ b/mm/internal.h > > @@ -492,6 +492,7 @@ struct compact_control { > > */ > > bool alloc_contig; /* alloc_contig_range allocation */ > > bool source_has_metadata; /* source pages have associated metadata */ > > + bool reserve_metadata; > > }; > > > > /* > > -- > > 2.41.0 > >