From: John Donnelly <John.p.donnelly@oracle.com> To: Baoquan He <bhe@redhat.com>, linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, akpm@linux-foundation.org, hch@lst.de, robin.murphy@arm.com, cl@linux.com, penberg@kernel.org, rientjes@google.com, iamjoonsoo.kim@lge.com, vbabka@suse.cz, m.szyprowski@samsung.com, kexec@lists.infradead.org Subject: Re: [PATCH RESEND v2 3/5] mm_zone: add function to check if managed dma zone exists Date: Mon, 6 Dec 2021 21:53:49 -0600 [thread overview] Message-ID: <23aab424-0937-4ef5-8af9-7c78a2f1b541@oracle.com> (raw) In-Reply-To: <20211207030750.30824-4-bhe@redhat.com> On 12/6/21 9:07 PM, Baoquan He wrote: > In some places of the current kernel, it assumes that dma zone must have > managed pages if CONFIG_ZONE_DMA is enabled. While this is not always true. > E.g in kdump kernel of x86_64, only low 1M is presented and locked down > at very early stage of boot, so that there's no managed pages at all in > DMA zone. This exception will always cause page allocation failure if page > is requested from DMA zone. > > Here add function has_managed_dma() and the relevant helper functions to > check if there's DMA zone with managed pages. It will be used in later > patches. > > Signed-off-by: Baoquan He <bhe@redhat.com> Reviewed-by: John Donnelly <john.p.donnelly@oracle.com> Tested-by: John Donnelly <john.p.donnelly@oracle.com> > --- > include/linux/mmzone.h | 21 +++++++++++++++++++++ > mm/page_alloc.c | 11 +++++++++++ > 2 files changed, 32 insertions(+) > > diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h > index 58e744b78c2c..82d23e13e0e5 100644 > --- a/include/linux/mmzone.h > +++ b/include/linux/mmzone.h > @@ -998,6 +998,18 @@ static inline bool zone_is_zone_device(struct zone *zone) > } > #endif > > +#ifdef CONFIG_ZONE_DMA > +static inline bool zone_is_dma(struct zone *zone) > +{ > + return zone_idx(zone) == ZONE_DMA; > +} > +#else > +static inline bool zone_is_dma(struct zone *zone) > +{ > + return false; > +} > +#endif > + > /* > * Returns true if a zone has pages managed by the buddy allocator. > * All the reclaim decisions have to use this function rather than > @@ -1046,6 +1058,7 @@ static inline int is_highmem_idx(enum zone_type idx) > #endif > } > > +bool has_managed_dma(void); > /** > * is_highmem - helper function to quickly check if a struct zone is a > * highmem zone or not. This is an attempt to keep references > @@ -1131,6 +1144,14 @@ extern struct zone *next_zone(struct zone *zone); > ; /* do nothing */ \ > else > > +#define for_each_managed_zone(zone) \ > + for (zone = (first_online_pgdat())->node_zones; \ > + zone; \ > + zone = next_zone(zone)) \ > + if (!managed_zone(zone)) \ > + ; /* do nothing */ \ > + else > + > static inline struct zone *zonelist_zone(struct zoneref *zoneref) > { > return zoneref->zone; > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index c5952749ad40..ac0ea42a4e5f 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -9459,4 +9459,15 @@ bool take_page_off_buddy(struct page *page) > spin_unlock_irqrestore(&zone->lock, flags); > return ret; > } > + > +bool has_managed_dma(void) > +{ > + struct zone *zone; > + > + for_each_managed_zone(zone) { > + if (zone_is_dma(zone)) > + return true; > + } > + return false; > +} > #endif >
WARNING: multiple messages have this Message-ID (diff)
From: John Donnelly <John.p.donnelly@oracle.com> To: Baoquan He <bhe@redhat.com>, linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, akpm@linux-foundation.org, hch@lst.de, robin.murphy@arm.com, cl@linux.com, penberg@kernel.org, rientjes@google.com, iamjoonsoo.kim@lge.com, vbabka@suse.cz, m.szyprowski@samsung.com, kexec@lists.infradead.org Subject: Re: [PATCH RESEND v2 3/5] mm_zone: add function to check if managed dma zone exists Date: Mon, 6 Dec 2021 21:53:49 -0600 [thread overview] Message-ID: <23aab424-0937-4ef5-8af9-7c78a2f1b541@oracle.com> (raw) In-Reply-To: <20211207030750.30824-4-bhe@redhat.com> On 12/6/21 9:07 PM, Baoquan He wrote: > In some places of the current kernel, it assumes that dma zone must have > managed pages if CONFIG_ZONE_DMA is enabled. While this is not always true. > E.g in kdump kernel of x86_64, only low 1M is presented and locked down > at very early stage of boot, so that there's no managed pages at all in > DMA zone. This exception will always cause page allocation failure if page > is requested from DMA zone. > > Here add function has_managed_dma() and the relevant helper functions to > check if there's DMA zone with managed pages. It will be used in later > patches. > > Signed-off-by: Baoquan He <bhe@redhat.com> Reviewed-by: John Donnelly <john.p.donnelly@oracle.com> Tested-by: John Donnelly <john.p.donnelly@oracle.com> > --- > include/linux/mmzone.h | 21 +++++++++++++++++++++ > mm/page_alloc.c | 11 +++++++++++ > 2 files changed, 32 insertions(+) > > diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h > index 58e744b78c2c..82d23e13e0e5 100644 > --- a/include/linux/mmzone.h > +++ b/include/linux/mmzone.h > @@ -998,6 +998,18 @@ static inline bool zone_is_zone_device(struct zone *zone) > } > #endif > > +#ifdef CONFIG_ZONE_DMA > +static inline bool zone_is_dma(struct zone *zone) > +{ > + return zone_idx(zone) == ZONE_DMA; > +} > +#else > +static inline bool zone_is_dma(struct zone *zone) > +{ > + return false; > +} > +#endif > + > /* > * Returns true if a zone has pages managed by the buddy allocator. > * All the reclaim decisions have to use this function rather than > @@ -1046,6 +1058,7 @@ static inline int is_highmem_idx(enum zone_type idx) > #endif > } > > +bool has_managed_dma(void); > /** > * is_highmem - helper function to quickly check if a struct zone is a > * highmem zone or not. This is an attempt to keep references > @@ -1131,6 +1144,14 @@ extern struct zone *next_zone(struct zone *zone); > ; /* do nothing */ \ > else > > +#define for_each_managed_zone(zone) \ > + for (zone = (first_online_pgdat())->node_zones; \ > + zone; \ > + zone = next_zone(zone)) \ > + if (!managed_zone(zone)) \ > + ; /* do nothing */ \ > + else > + > static inline struct zone *zonelist_zone(struct zoneref *zoneref) > { > return zoneref->zone; > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index c5952749ad40..ac0ea42a4e5f 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -9459,4 +9459,15 @@ bool take_page_off_buddy(struct page *page) > spin_unlock_irqrestore(&zone->lock, flags); > return ret; > } > + > +bool has_managed_dma(void) > +{ > + struct zone *zone; > + > + for_each_managed_zone(zone) { > + if (zone_is_dma(zone)) > + return true; > + } > + return false; > +} > #endif > _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec
next prev parent reply other threads:[~2021-12-07 3:54 UTC|newest] Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-12-07 3:07 [PATCH RESEND v2 0/5] Avoid requesting page from DMA zone when no managed pages Baoquan He 2021-12-07 3:07 ` Baoquan He 2021-12-07 3:07 ` [PATCH RESEND v2 1/5] docs: kernel-parameters: Update to reflect the current default size of atomic pool Baoquan He 2021-12-07 3:07 ` Baoquan He 2021-12-07 3:53 ` John Donnelly 2021-12-07 3:53 ` John Donnelly 2021-12-07 3:07 ` [PATCH RESEND v2 2/5] dma-pool: allow user to disable " Baoquan He 2021-12-07 3:07 ` Baoquan He 2021-12-07 3:53 ` John Donnelly 2021-12-07 3:53 ` John Donnelly 2021-12-13 7:44 ` Christoph Hellwig 2021-12-13 7:44 ` Christoph Hellwig 2021-12-13 8:16 ` Baoquan He 2021-12-13 8:16 ` Baoquan He 2021-12-07 3:07 ` [PATCH RESEND v2 3/5] mm_zone: add function to check if managed dma zone exists Baoquan He 2021-12-07 3:07 ` Baoquan He 2021-12-07 3:53 ` John Donnelly [this message] 2021-12-07 3:53 ` John Donnelly 2021-12-07 11:23 ` David Hildenbrand 2021-12-07 11:23 ` David Hildenbrand 2021-12-09 13:02 ` Baoquan He 2021-12-09 13:02 ` Baoquan He 2021-12-09 13:10 ` David Hildenbrand 2021-12-09 13:10 ` David Hildenbrand 2021-12-09 13:23 ` Baoquan He 2021-12-09 13:23 ` Baoquan He 2021-12-07 3:07 ` [PATCH RESEND v2 4/5] dma/pool: create dma atomic pool only if dma zone has managed pages Baoquan He 2021-12-07 3:07 ` Baoquan He 2021-12-07 3:07 ` Baoquan He 2021-12-07 3:54 ` John Donnelly 2021-12-07 3:54 ` John Donnelly 2021-12-07 3:54 ` John Donnelly 2021-12-07 3:07 ` [PATCH RESEND v2 5/5] mm/slub: do not create dma-kmalloc if no managed pages in DMA zone Baoquan He 2021-12-07 3:07 ` Baoquan He 2021-12-07 3:54 ` John Donnelly 2021-12-07 3:54 ` John Donnelly 2021-12-07 3:16 ` [PATCH RESEND v2 0/5] Avoid requesting page from DMA zone when no managed pages Baoquan He 2021-12-07 3:16 ` Baoquan He 2021-12-07 4:03 ` John Donnelly 2021-12-07 4:03 ` John Donnelly 2021-12-08 4:33 ` Andrew Morton 2021-12-08 4:33 ` Andrew Morton 2021-12-08 4:56 ` John Donnelly 2021-12-08 4:56 ` John Donnelly 2021-12-13 3:54 ` Baoquan He 2021-12-13 3:54 ` Baoquan He 2021-12-13 13:25 ` Borislav Petkov 2021-12-13 13:25 ` Borislav Petkov 2021-12-13 14:03 ` Baoquan He 2021-12-13 14:03 ` Baoquan He 2021-12-07 8:05 ` Christoph Lameter 2021-12-07 8:05 ` Christoph Lameter 2021-12-09 8:05 ` Baoquan He 2021-12-09 8:05 ` Baoquan He 2021-12-09 12:59 ` Christoph Lameter 2021-12-09 12:59 ` Christoph Lameter 2021-12-13 7:39 ` Baoquan He 2021-12-13 7:39 ` Baoquan He 2021-12-13 7:49 ` Christoph Hellwig 2021-12-13 7:49 ` Christoph Hellwig 2021-12-13 14:21 ` Hyeonggon Yoo 2021-12-13 14:21 ` Hyeonggon Yoo 2021-12-13 7:47 ` Christoph Hellwig 2021-12-13 7:47 ` Christoph Hellwig
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=23aab424-0937-4ef5-8af9-7c78a2f1b541@oracle.com \ --to=john.p.donnelly@oracle.com \ --cc=akpm@linux-foundation.org \ --cc=bhe@redhat.com \ --cc=cl@linux.com \ --cc=hch@lst.de \ --cc=iamjoonsoo.kim@lge.com \ --cc=kexec@lists.infradead.org \ --cc=linux-kernel@vger.kernel.org \ --cc=linux-mm@kvack.org \ --cc=m.szyprowski@samsung.com \ --cc=penberg@kernel.org \ --cc=rientjes@google.com \ --cc=robin.murphy@arm.com \ --cc=vbabka@suse.cz \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.