* Re: [PATCH v6 08/10] mm/memory_hotplug: Don't check for "all holes" in shrink_zone_span()
From: David Hildenbrand @ 2020-02-05 14:55 UTC (permalink / raw)
To: David Laight, 'Wei Yang'
Cc: linux-s390@vger.kernel.org, Michal Hocko,
linux-ia64@vger.kernel.org, Pavel Tatashin,
linux-sh@vger.kernel.org, x86@kernel.org,
linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andrew Morton,
linuxppc-dev@lists.ozlabs.org, Dan Williams,
linux-arm-kernel@lists.infradead.org, Oscar Salvador
In-Reply-To: <b8f142b9d569459d84b71949cb5efc27@AcuMS.aculab.com>
On 05.02.20 15:54, David Laight wrote:
> From: Wei Yang
>> Sent: 05 February 2020 09:59
> ...
>> If it is me, I would like to take out these two similar logic out.
>>
>> For example:
>>
>> if () {
>> } else if () {
>> } else {
>> goto out;
>> }
>
> I'm pretty sure the kernel layout rules disallow 'else if'.
Huh?
git grep "else if" | wc -l
49336
I'm afraid I don't get what you mean :)
--
Thanks,
David / dhildenb
^ permalink raw reply
* RE: [PATCH v6 08/10] mm/memory_hotplug: Don't check for "all holes" in shrink_zone_span()
From: David Laight @ 2020-02-05 14:54 UTC (permalink / raw)
To: 'Wei Yang', David Hildenbrand
Cc: linux-s390@vger.kernel.org, Michal Hocko,
linux-ia64@vger.kernel.org, Pavel Tatashin,
linux-sh@vger.kernel.org, x86@kernel.org,
linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andrew Morton,
linuxppc-dev@lists.ozlabs.org, Dan Williams,
linux-arm-kernel@lists.infradead.org, Oscar Salvador
In-Reply-To: <20200205095924.GC24162@richard>
From: Wei Yang
> Sent: 05 February 2020 09:59
...
> If it is me, I would like to take out these two similar logic out.
>
> For example:
>
> if () {
> } else if () {
> } else {
> goto out;
> }
I'm pretty sure the kernel layout rules disallow 'else if'.
It is also pretty horrid unless the conditionals are all related
(so it is almost a switch statement).
David
-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
^ permalink raw reply
* Re: [PATCH v6 08/10] mm/memory_hotplug: Don't check for "all holes" in shrink_zone_span()
From: Baoquan He @ 2020-02-05 14:48 UTC (permalink / raw)
To: Wei Yang
Cc: linux-s390, x86, linux-ia64, Pavel Tatashin, David Hildenbrand,
linux-sh, linux-kernel, linux-mm, Michal Hocko, Andrew Morton,
linuxppc-dev, Dan Williams, linux-arm-kernel, Oscar Salvador
In-Reply-To: <20200205095924.GC24162@richard>
Hi Wei Yang,
On 02/05/20 at 05:59pm, Wei Yang wrote:
> >diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> >index f294918f7211..8dafa1ba8d9f 100644
> >--- a/mm/memory_hotplug.c
> >+++ b/mm/memory_hotplug.c
> >@@ -393,6 +393,9 @@ static void shrink_zone_span(struct zone *zone, unsigned long start_pfn,
> > if (pfn) {
> > zone->zone_start_pfn = pfn;
> > zone->spanned_pages = zone_end_pfn - pfn;
> >+ } else {
> >+ zone->zone_start_pfn = 0;
> >+ zone->spanned_pages = 0;
> > }
> > } else if (zone_end_pfn == end_pfn) {
> > /*
> >@@ -405,34 +408,11 @@ static void shrink_zone_span(struct zone *zone, unsigned long start_pfn,
> > start_pfn);
> > if (pfn)
> > zone->spanned_pages = pfn - zone_start_pfn + 1;
> >+ else {
> >+ zone->zone_start_pfn = 0;
> >+ zone->spanned_pages = 0;
> >+ }
> > }
>
> If it is me, I would like to take out these two similar logic out.
I also like this style.
>
> For example:
>
> if () {
> } else if () {
> } else {
> goto out;
Here the last else is unnecessary, right?
> }
>
>
Like this, I believe both David and I will be satisfactory. Even though
I still think his 2nd resetting is not needed :-)
> /* The zone has no valid section */
> if (!pfn) {
> zone->zone_start_pfn = 0;
> zone->spanned_pages = 0;
> }
>
> out:
> zone_span_writeunlock(zone);
>
> Well, this is just my personal taste :-)
>
> >-
> >- /*
> >- * The section is not biggest or smallest mem_section in the zone, it
> >- * only creates a hole in the zone. So in this case, we need not
> >- * change the zone. But perhaps, the zone has only hole data. Thus
> >- * it check the zone has only hole or not.
> >- */
> >- pfn = zone_start_pfn;
> >- for (; pfn < zone_end_pfn; pfn += PAGES_PER_SUBSECTION) {
> >- if (unlikely(!pfn_to_online_page(pfn)))
> >- continue;
> >-
> >- if (page_zone(pfn_to_page(pfn)) != zone)
> >- continue;
> >-
> >- /* Skip range to be removed */
> >- if (pfn >= start_pfn && pfn < end_pfn)
> >- continue;
> >-
> >- /* If we find valid section, we have nothing to do */
> >- zone_span_writeunlock(zone);
> >- return;
> >- }
> >-
> >- /* The zone has no valid section */
> >- zone->zone_start_pfn = 0;
> >- zone->spanned_pages = 0;
> > zone_span_writeunlock(zone);
> > }
> >
> >--
> >2.21.0
>
> --
> Wei Yang
> Help you, Help me
>
^ permalink raw reply
* Re: [PATCH v2 1/3] powerpc/tm: Clear the current thread's MSR[TS] after treclaim
From: Sasha Levin @ 2020-02-05 14:45 UTC (permalink / raw)
To: Sasha Levin, Gustavo Luiz Duarte, linuxppc-dev; +Cc: mikey, stable, gromero
In-Reply-To: <20200203160906.24482-1-gustavold@linux.ibm.com>
Hi,
[This is an automated email]
This commit has been processed because it contains a "Fixes:" tag,
fixing commit: 2b0a576d15e0 ("powerpc: Add new transactional memory state to the signal context").
The bot has tested the following trees: v5.5.1, v5.4.17, v4.19.101, v4.14.169, v4.9.212, v4.4.212.
v5.5.1: Build OK!
v5.4.17: Build OK!
v4.19.101: Build OK!
v4.14.169: Failed to apply! Possible dependencies:
1c200e63d055 ("powerpc/tm: Fix endianness flip on trap")
92fb8690bd04 ("powerpc/tm: P9 disable transactionally suspended sigcontexts")
v4.9.212: Failed to apply! Possible dependencies:
1c200e63d055 ("powerpc/tm: Fix endianness flip on trap")
92fb8690bd04 ("powerpc/tm: P9 disable transactionally suspended sigcontexts")
v4.4.212: Failed to apply! Possible dependencies:
1c200e63d055 ("powerpc/tm: Fix endianness flip on trap")
92fb8690bd04 ("powerpc/tm: P9 disable transactionally suspended sigcontexts")
a7d623d4d053 ("powerpc: Move part of giveup_vsx into c")
b86fd2bd0302 ("powerpc: Simplify TM restore checks")
d11994314b2b ("powerpc: signals: Stop using current in signal code")
d96f234f47af ("powerpc: Avoid load hit store in setup_sigcontext()")
e1c0d66fcb17 ("powerpc: Set used_(vsr|vr|spe) in sigreturn path when MSR bits are active")
NOTE: The patch will not be queued to stable trees until it is upstream.
How should we proceed with this patch?
--
Thanks,
Sasha
^ permalink raw reply
* Re: [PATCH] powerpc/drmem: cache LMBs in xarray to accelerate lookup
From: Fontenot, Nathan @ 2020-02-05 14:33 UTC (permalink / raw)
To: Scott Cheloha, Nathan Lynch; +Cc: linuxppc-dev, linux-kernel, Rick Lindsley
In-Reply-To: <20200203201346.deqkxwgfmkifeb5s@rascal.austin.ibm.com>
On 2/3/2020 2:13 PM, Scott Cheloha wrote:
> On Thu, Jan 30, 2020 at 10:09:32AM -0600, Fontenot, Nathan wrote:
>> On 1/29/2020 12:10 PM, Scott Cheloha wrote:
>>> On Tue, Jan 28, 2020 at 05:56:55PM -0600, Nathan Lynch wrote:
>>>> Scott Cheloha <cheloha@linux.ibm.com> writes:
>>>>> LMB lookup is currently an O(n) linear search. This scales poorly when
>>>>> there are many LMBs.
>>>>>
>>>>> If we cache each LMB by both its base address and its DRC index
>>>>> in an xarray we can cut lookups to O(log n), greatly accelerating
>>>>> drmem initialization and memory hotplug.
>>>>>
>>>>> This patch introduces two xarrays of of LMBs and fills them during
>>>>> drmem initialization. The patch also adds two interfaces for LMB
>>>>> lookup.
>>>>
>>>> Good but can you replace the array of LMBs altogether
>>>> (drmem_info->lmbs)? xarray allows iteration over the members if needed.
>>>
>>> I don't think we can without potentially changing the current behavior.
>>>
>>> The current behavior in dlpar_memory_{add,remove}_by_ic() is to advance
>>> linearly through the array from the LMB with the matching DRC index.
>>>
>>> Iteration through the xarray via xa_for_each_start() will return LMBs
>>> indexed with monotonically increasing DRC indices.>
>>> Are they equivalent? Or can we have an LMB with a smaller DRC index
>>> appear at a greater offset in the array?
>>>
>>> If the following condition is possible:
>>>
>>> drmem_info->lmbs[i].drc_index > drmem_info->lmbs[j].drc_index
>>>
>>> where i < j, then we have a possible behavior change because
>>> xa_for_each_start() may not return a contiguous array slice. It might
>>> "leap backwards" in the array. Or it might skip over a chunk of LMBs.
>>>
>>
>> The LMB array should have each LMB in monotonically increasing DRC Index
>> value. Note that this is set up based on the DT property but I don't recall
>> ever seeing the DT specify LMBs out of order or not being contiguous.
>
> Is that ordering guaranteed by the PAPR or some other spec or is that
> just a convention?
From what I remember the PAPR does not specify that DRC indexes are guaranteed
to be contiguous. In past discussions with pHyp developers I had been told that
they always generate contiguous DRC index values but without a specification in
the PAPR that could always break.
-Nathan
>
> Code like drmem_update_dt_v1() makes me very nervous:
>
> static int drmem_update_dt_v1(struct device_node *memory,
> struct property *prop)
> {
> struct property *new_prop;
> struct of_drconf_cell_v1 *dr_cell;
> struct drmem_lmb *lmb;
> u32 *p;
>
> new_prop = clone_property(prop, prop->length);
> if (!new_prop)
> return -1;
>
> p = new_prop->value;
> *p++ = cpu_to_be32(drmem_info->n_lmbs);
>
> dr_cell = (struct of_drconf_cell_v1 *)p;
>
> for_each_drmem_lmb(lmb) {
> dr_cell->base_addr = cpu_to_be64(lmb->base_addr);
> dr_cell->drc_index = cpu_to_be32(lmb->drc_index);
> dr_cell->aa_index = cpu_to_be32(lmb->aa_index);
> dr_cell->flags = cpu_to_be32(drmem_lmb_flags(lmb));
>
> dr_cell++;
> }
>
> of_update_property(memory, new_prop);
> return 0;
> }
>
> If for whatever reason the firmware has a DRC that isn't monotonically
> increasing and we update a firmware property at the wrong offset I have
> no idea what would happen.
>
> With the array we preserve the order. Without it we might violate
> some assumption the firmware has made.
>
^ permalink raw reply
* Re: [PATCH v6 08/10] mm/memory_hotplug: Don't check for "all holes" in shrink_zone_span()
From: Baoquan He @ 2020-02-05 14:26 UTC (permalink / raw)
To: David Hildenbrand
Cc: linux-s390, Michal Hocko, linux-ia64, Pavel Tatashin, linux-sh,
x86, linux-kernel, linux-mm, Wei Yang, Andrew Morton,
linuxppc-dev, Dan Williams, linux-arm-kernel, Oscar Salvador
In-Reply-To: <be8b9c0e-0929-4ea4-9c25-15e1f221dfb1@redhat.com>
On 02/05/20 at 03:16pm, David Hildenbrand wrote:
> >>>> Anyhow, that patch is already upstream and I don't consider this high
> >>>> priority. Thanks :)
> >>>
> >>> Yeah, noticed you told Wei the status in another patch thread, I am fine
> >>> with it, just leave it to you to decide. Thanks.
> >>
> >> I am fairly busy right now. Can you send a patch (double-checking and
> >> making this eventually unconditional?). Thanks!
> >
> > Understood, sorry about the noise, David. I will think about this.
> >
>
> No need to excuse, really, I'm very happy about review feedback!
>
Glad to hear it, thanks.
> The review of this series happened fairly late. Bad, because it's not
> perfect, but good, because no serious stuff was found (so far :) ). If
> you also don't have time to look into this, I can put it onto my todo
> list, just let me know.
Both is OK to me, as long as thing is clear to us. I will discuss with
Wei Yang for now. You can post patch anytime if you make one.
^ permalink raw reply
* Re: [PATCH v6 08/10] mm/memory_hotplug: Don't check for "all holes" in shrink_zone_span()
From: David Hildenbrand @ 2020-02-05 14:16 UTC (permalink / raw)
To: Baoquan He
Cc: linux-s390, Michal Hocko, linux-ia64, Pavel Tatashin, linux-sh,
x86, linux-kernel, linux-mm, Wei Yang, Andrew Morton,
linuxppc-dev, Dan Williams, linux-arm-kernel, Oscar Salvador
In-Reply-To: <20200205141254.GD8965@MiWiFi-R3L-srv>
>>>> Anyhow, that patch is already upstream and I don't consider this high
>>>> priority. Thanks :)
>>>
>>> Yeah, noticed you told Wei the status in another patch thread, I am fine
>>> with it, just leave it to you to decide. Thanks.
>>
>> I am fairly busy right now. Can you send a patch (double-checking and
>> making this eventually unconditional?). Thanks!
>
> Understood, sorry about the noise, David. I will think about this.
>
No need to excuse, really, I'm very happy about review feedback!
The review of this series happened fairly late. Bad, because it's not
perfect, but good, because no serious stuff was found (so far :) ). If
you also don't have time to look into this, I can put it onto my todo
list, just let me know.
Thanks!
--
Thanks,
David / dhildenb
^ permalink raw reply
* Re: [PATCH v6 08/10] mm/memory_hotplug: Don't check for "all holes" in shrink_zone_span()
From: Baoquan He @ 2020-02-05 14:12 UTC (permalink / raw)
To: David Hildenbrand
Cc: linux-s390, Michal Hocko, linux-ia64, Pavel Tatashin, linux-sh,
x86, linux-kernel, linux-mm, Wei Yang, Andrew Morton,
linuxppc-dev, Dan Williams, linux-arm-kernel, Oscar Salvador
In-Reply-To: <2868343a-745b-e2b6-7e78-d5649c00ee31@redhat.com>
On 02/05/20 at 02:38pm, David Hildenbrand wrote:
> On 05.02.20 14:34, Baoquan He wrote:
> > On 02/05/20 at 02:20pm, David Hildenbrand wrote:
> >> On 05.02.20 13:43, Baoquan He wrote:
> >>> On 02/04/20 at 03:42pm, David Hildenbrand wrote:
> >>>> On 04.02.20 15:25, Baoquan He wrote:
> >>>>> On 10/06/19 at 10:56am, David Hildenbrand wrote:
> >>>>>> If we have holes, the holes will automatically get detected and removed
> >>>>>> once we remove the next bigger/smaller section. The extra checks can
> >>>>>> go.
> >>>>>>
> >>>>>> Cc: Andrew Morton <akpm@linux-foundation.org>
> >>>>>> Cc: Oscar Salvador <osalvador@suse.de>
> >>>>>> Cc: Michal Hocko <mhocko@suse.com>
> >>>>>> Cc: David Hildenbrand <david@redhat.com>
> >>>>>> Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
> >>>>>> Cc: Dan Williams <dan.j.williams@intel.com>
> >>>>>> Cc: Wei Yang <richardw.yang@linux.intel.com>
> >>>>>> Signed-off-by: David Hildenbrand <david@redhat.com>
> >>>>>> ---
> >>>>>> mm/memory_hotplug.c | 34 +++++++---------------------------
> >>>>>> 1 file changed, 7 insertions(+), 27 deletions(-)
> >>>>>>
> >>>>>> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> >>>>>> index f294918f7211..8dafa1ba8d9f 100644
> >>>>>> --- a/mm/memory_hotplug.c
> >>>>>> +++ b/mm/memory_hotplug.c
> >>>>>> @@ -393,6 +393,9 @@ static void shrink_zone_span(struct zone *zone, unsigned long start_pfn,
> >>>>>> if (pfn) {
> >>>>>> zone->zone_start_pfn = pfn;
> >>>>>> zone->spanned_pages = zone_end_pfn - pfn;
> >>>>>> + } else {
> >>>>>> + zone->zone_start_pfn = 0;
> >>>>>> + zone->spanned_pages = 0;
> >>>>>> }
> >>>>>> } else if (zone_end_pfn == end_pfn) {
> >>>>>> /*
> >>>>>> @@ -405,34 +408,11 @@ static void shrink_zone_span(struct zone *zone, unsigned long start_pfn,
> >>>>>> start_pfn);
> >>>>>> if (pfn)
> >>>>>> zone->spanned_pages = pfn - zone_start_pfn + 1;
> >>>>>> + else {
> >>>>>> + zone->zone_start_pfn = 0;
> >>>>>> + zone->spanned_pages = 0;
> >>>>>
> >>>>> Thinking in which case (zone_start_pfn != start_pfn) and it comes here.
> >>>>
> >>>> Could only happen in case the zone_start_pfn would have been "out of the
> >>>> zone already". If you ask me: unlikely :)
> >>>
> >>> Yeah, I also think it's unlikely to come here.
> >>>
> >>> The 'if (zone_start_pfn == start_pfn)' checking also covers the case
> >>> (zone_start_pfn == start_pfn && zone_end_pfn == end_pfn). So this
> >>> zone_start_pfn/spanned_pages resetting can be removed to avoid
> >>> confusion.
> >>
> >> At least I would find it more confusing without it (or want a comment
> >> explaining why this does not have to be handled and why the !pfn case is
> >> not possible).
> >
> > I don't get why being w/o it will be more confusing, but it's OK since
> > it doesn't impact anything.
>
> Because we could actually BUG_ON(!pfn) here, right? Only having a "if
> (pfn)" leaves the reader wondering "why is the other case not handled".
>
> >
> >>
> >> Anyhow, that patch is already upstream and I don't consider this high
> >> priority. Thanks :)
> >
> > Yeah, noticed you told Wei the status in another patch thread, I am fine
> > with it, just leave it to you to decide. Thanks.
>
> I am fairly busy right now. Can you send a patch (double-checking and
> making this eventually unconditional?). Thanks!
Understood, sorry about the noise, David. I will think about this.
^ permalink raw reply
* Re: [RFC] per-CPU usage in perf core-book3s
From: Sebastian Andrzej Siewior @ 2020-02-05 14:11 UTC (permalink / raw)
To: maddy
Cc: Mark Rutland, Peter Zijlstra, Jiri Olsa, linux-kernel,
Arnaldo Carvalho de Melo, Alexander Shishkin, Ingo Molnar,
Paul Mackerras, Namhyung Kim, Thomas Gleixner, linuxppc-dev
In-Reply-To: <c26f6c2c-980f-c1b2-ff7c-7a5e2a5771cd@linux.ibm.com>
On 2020-02-05 07:10:59 [+0530], maddy wrote:
> Yes, currently we dont have anything that prevents the timer
> callback to interrupt pmu::event_init. Nice catch. Thanks for
> pointing this out.
You are welcome.
> Looking at the code, per-cpu variable access are made to
> check for constraints and for Branch Stack (BHRB). So could
> wrap this block of pmu::event_init with local_irq_save/restore.
> Will send a patch to fix it.
Okay. Please keep me in the loop :)
>
> Maddy
Sebastian
^ permalink raw reply
* Re: [PATCH v6 08/10] mm/memory_hotplug: Don't check for "all holes" in shrink_zone_span()
From: David Hildenbrand @ 2020-02-05 13:38 UTC (permalink / raw)
To: Baoquan He
Cc: linux-s390, Michal Hocko, linux-ia64, Pavel Tatashin, linux-sh,
x86, linux-kernel, linux-mm, Wei Yang, Andrew Morton,
linuxppc-dev, Dan Williams, linux-arm-kernel, Oscar Salvador
In-Reply-To: <20200205133442.GC8965@MiWiFi-R3L-srv>
On 05.02.20 14:34, Baoquan He wrote:
> On 02/05/20 at 02:20pm, David Hildenbrand wrote:
>> On 05.02.20 13:43, Baoquan He wrote:
>>> On 02/04/20 at 03:42pm, David Hildenbrand wrote:
>>>> On 04.02.20 15:25, Baoquan He wrote:
>>>>> On 10/06/19 at 10:56am, David Hildenbrand wrote:
>>>>>> If we have holes, the holes will automatically get detected and removed
>>>>>> once we remove the next bigger/smaller section. The extra checks can
>>>>>> go.
>>>>>>
>>>>>> Cc: Andrew Morton <akpm@linux-foundation.org>
>>>>>> Cc: Oscar Salvador <osalvador@suse.de>
>>>>>> Cc: Michal Hocko <mhocko@suse.com>
>>>>>> Cc: David Hildenbrand <david@redhat.com>
>>>>>> Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
>>>>>> Cc: Dan Williams <dan.j.williams@intel.com>
>>>>>> Cc: Wei Yang <richardw.yang@linux.intel.com>
>>>>>> Signed-off-by: David Hildenbrand <david@redhat.com>
>>>>>> ---
>>>>>> mm/memory_hotplug.c | 34 +++++++---------------------------
>>>>>> 1 file changed, 7 insertions(+), 27 deletions(-)
>>>>>>
>>>>>> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
>>>>>> index f294918f7211..8dafa1ba8d9f 100644
>>>>>> --- a/mm/memory_hotplug.c
>>>>>> +++ b/mm/memory_hotplug.c
>>>>>> @@ -393,6 +393,9 @@ static void shrink_zone_span(struct zone *zone, unsigned long start_pfn,
>>>>>> if (pfn) {
>>>>>> zone->zone_start_pfn = pfn;
>>>>>> zone->spanned_pages = zone_end_pfn - pfn;
>>>>>> + } else {
>>>>>> + zone->zone_start_pfn = 0;
>>>>>> + zone->spanned_pages = 0;
>>>>>> }
>>>>>> } else if (zone_end_pfn == end_pfn) {
>>>>>> /*
>>>>>> @@ -405,34 +408,11 @@ static void shrink_zone_span(struct zone *zone, unsigned long start_pfn,
>>>>>> start_pfn);
>>>>>> if (pfn)
>>>>>> zone->spanned_pages = pfn - zone_start_pfn + 1;
>>>>>> + else {
>>>>>> + zone->zone_start_pfn = 0;
>>>>>> + zone->spanned_pages = 0;
>>>>>
>>>>> Thinking in which case (zone_start_pfn != start_pfn) and it comes here.
>>>>
>>>> Could only happen in case the zone_start_pfn would have been "out of the
>>>> zone already". If you ask me: unlikely :)
>>>
>>> Yeah, I also think it's unlikely to come here.
>>>
>>> The 'if (zone_start_pfn == start_pfn)' checking also covers the case
>>> (zone_start_pfn == start_pfn && zone_end_pfn == end_pfn). So this
>>> zone_start_pfn/spanned_pages resetting can be removed to avoid
>>> confusion.
>>
>> At least I would find it more confusing without it (or want a comment
>> explaining why this does not have to be handled and why the !pfn case is
>> not possible).
>
> I don't get why being w/o it will be more confusing, but it's OK since
> it doesn't impact anything.
Because we could actually BUG_ON(!pfn) here, right? Only having a "if
(pfn)" leaves the reader wondering "why is the other case not handled".
>
>>
>> Anyhow, that patch is already upstream and I don't consider this high
>> priority. Thanks :)
>
> Yeah, noticed you told Wei the status in another patch thread, I am fine
> with it, just leave it to you to decide. Thanks.
I am fairly busy right now. Can you send a patch (double-checking and
making this eventually unconditional?). Thanks!
--
Thanks,
David / dhildenb
^ permalink raw reply
* Re: [PATCH v6 08/10] mm/memory_hotplug: Don't check for "all holes" in shrink_zone_span()
From: Baoquan He @ 2020-02-05 13:34 UTC (permalink / raw)
To: David Hildenbrand
Cc: linux-s390, Michal Hocko, linux-ia64, Pavel Tatashin, linux-sh,
x86, linux-kernel, linux-mm, Wei Yang, Andrew Morton,
linuxppc-dev, Dan Williams, linux-arm-kernel, Oscar Salvador
In-Reply-To: <cd353848-301a-025d-dd66-44d76e1bbc44@redhat.com>
On 02/05/20 at 02:20pm, David Hildenbrand wrote:
> On 05.02.20 13:43, Baoquan He wrote:
> > On 02/04/20 at 03:42pm, David Hildenbrand wrote:
> >> On 04.02.20 15:25, Baoquan He wrote:
> >>> On 10/06/19 at 10:56am, David Hildenbrand wrote:
> >>>> If we have holes, the holes will automatically get detected and removed
> >>>> once we remove the next bigger/smaller section. The extra checks can
> >>>> go.
> >>>>
> >>>> Cc: Andrew Morton <akpm@linux-foundation.org>
> >>>> Cc: Oscar Salvador <osalvador@suse.de>
> >>>> Cc: Michal Hocko <mhocko@suse.com>
> >>>> Cc: David Hildenbrand <david@redhat.com>
> >>>> Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
> >>>> Cc: Dan Williams <dan.j.williams@intel.com>
> >>>> Cc: Wei Yang <richardw.yang@linux.intel.com>
> >>>> Signed-off-by: David Hildenbrand <david@redhat.com>
> >>>> ---
> >>>> mm/memory_hotplug.c | 34 +++++++---------------------------
> >>>> 1 file changed, 7 insertions(+), 27 deletions(-)
> >>>>
> >>>> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> >>>> index f294918f7211..8dafa1ba8d9f 100644
> >>>> --- a/mm/memory_hotplug.c
> >>>> +++ b/mm/memory_hotplug.c
> >>>> @@ -393,6 +393,9 @@ static void shrink_zone_span(struct zone *zone, unsigned long start_pfn,
> >>>> if (pfn) {
> >>>> zone->zone_start_pfn = pfn;
> >>>> zone->spanned_pages = zone_end_pfn - pfn;
> >>>> + } else {
> >>>> + zone->zone_start_pfn = 0;
> >>>> + zone->spanned_pages = 0;
> >>>> }
> >>>> } else if (zone_end_pfn == end_pfn) {
> >>>> /*
> >>>> @@ -405,34 +408,11 @@ static void shrink_zone_span(struct zone *zone, unsigned long start_pfn,
> >>>> start_pfn);
> >>>> if (pfn)
> >>>> zone->spanned_pages = pfn - zone_start_pfn + 1;
> >>>> + else {
> >>>> + zone->zone_start_pfn = 0;
> >>>> + zone->spanned_pages = 0;
> >>>
> >>> Thinking in which case (zone_start_pfn != start_pfn) and it comes here.
> >>
> >> Could only happen in case the zone_start_pfn would have been "out of the
> >> zone already". If you ask me: unlikely :)
> >
> > Yeah, I also think it's unlikely to come here.
> >
> > The 'if (zone_start_pfn == start_pfn)' checking also covers the case
> > (zone_start_pfn == start_pfn && zone_end_pfn == end_pfn). So this
> > zone_start_pfn/spanned_pages resetting can be removed to avoid
> > confusion.
>
> At least I would find it more confusing without it (or want a comment
> explaining why this does not have to be handled and why the !pfn case is
> not possible).
I don't get why being w/o it will be more confusing, but it's OK since
it doesn't impact anything.
>
> Anyhow, that patch is already upstream and I don't consider this high
> priority. Thanks :)
Yeah, noticed you told Wei the status in another patch thread, I am fine
with it, just leave it to you to decide. Thanks.
^ permalink raw reply
* Re: [PATCH v6 10/10] mm/memory_hotplug: Cleanup __remove_pages()
From: David Hildenbrand @ 2020-02-05 13:23 UTC (permalink / raw)
To: Segher Boessenkool
Cc: linux-s390, Michal Hocko, linux-ia64, Pavel Tatashin, linux-sh,
x86, linux-kernel, linux-mm, Wei Yang, Andrew Morton,
linuxppc-dev, Dan Williams, linux-arm-kernel, Oscar Salvador
In-Reply-To: <8f4752f5-c676-f56e-8cd2-239898aba2fd@redhat.com>
On 05.02.20 14:18, David Hildenbrand wrote:
>> I'm sorry to have to correct you again for some corner cases:
>>
>> ALIGN_UP(1, 4096) - 4096 = 0
>>
>> Again, not as easy as it seems ...
>>
>
> Eh, wait, I'm messing up things. Will double check :)
>
Yes, makes sense, will send a patch and cc you. Thanks!
--
Thanks,
David / dhildenb
^ permalink raw reply
* Re: [PATCH v6 08/10] mm/memory_hotplug: Don't check for "all holes" in shrink_zone_span()
From: David Hildenbrand @ 2020-02-05 13:20 UTC (permalink / raw)
To: Baoquan He
Cc: linux-s390, Michal Hocko, linux-ia64, Pavel Tatashin, linux-sh,
x86, linux-kernel, linux-mm, Wei Yang, Andrew Morton,
linuxppc-dev, Dan Williams, linux-arm-kernel, Oscar Salvador
In-Reply-To: <20200205124329.GE26758@MiWiFi-R3L-srv>
On 05.02.20 13:43, Baoquan He wrote:
> On 02/04/20 at 03:42pm, David Hildenbrand wrote:
>> On 04.02.20 15:25, Baoquan He wrote:
>>> On 10/06/19 at 10:56am, David Hildenbrand wrote:
>>>> If we have holes, the holes will automatically get detected and removed
>>>> once we remove the next bigger/smaller section. The extra checks can
>>>> go.
>>>>
>>>> Cc: Andrew Morton <akpm@linux-foundation.org>
>>>> Cc: Oscar Salvador <osalvador@suse.de>
>>>> Cc: Michal Hocko <mhocko@suse.com>
>>>> Cc: David Hildenbrand <david@redhat.com>
>>>> Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
>>>> Cc: Dan Williams <dan.j.williams@intel.com>
>>>> Cc: Wei Yang <richardw.yang@linux.intel.com>
>>>> Signed-off-by: David Hildenbrand <david@redhat.com>
>>>> ---
>>>> mm/memory_hotplug.c | 34 +++++++---------------------------
>>>> 1 file changed, 7 insertions(+), 27 deletions(-)
>>>>
>>>> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
>>>> index f294918f7211..8dafa1ba8d9f 100644
>>>> --- a/mm/memory_hotplug.c
>>>> +++ b/mm/memory_hotplug.c
>>>> @@ -393,6 +393,9 @@ static void shrink_zone_span(struct zone *zone, unsigned long start_pfn,
>>>> if (pfn) {
>>>> zone->zone_start_pfn = pfn;
>>>> zone->spanned_pages = zone_end_pfn - pfn;
>>>> + } else {
>>>> + zone->zone_start_pfn = 0;
>>>> + zone->spanned_pages = 0;
>>>> }
>>>> } else if (zone_end_pfn == end_pfn) {
>>>> /*
>>>> @@ -405,34 +408,11 @@ static void shrink_zone_span(struct zone *zone, unsigned long start_pfn,
>>>> start_pfn);
>>>> if (pfn)
>>>> zone->spanned_pages = pfn - zone_start_pfn + 1;
>>>> + else {
>>>> + zone->zone_start_pfn = 0;
>>>> + zone->spanned_pages = 0;
>>>
>>> Thinking in which case (zone_start_pfn != start_pfn) and it comes here.
>>
>> Could only happen in case the zone_start_pfn would have been "out of the
>> zone already". If you ask me: unlikely :)
>
> Yeah, I also think it's unlikely to come here.
>
> The 'if (zone_start_pfn == start_pfn)' checking also covers the case
> (zone_start_pfn == start_pfn && zone_end_pfn == end_pfn). So this
> zone_start_pfn/spanned_pages resetting can be removed to avoid
> confusion.
At least I would find it more confusing without it (or want a comment
explaining why this does not have to be handled and why the !pfn case is
not possible).
Anyhow, that patch is already upstream and I don't consider this high
priority. Thanks :)
--
Thanks,
David / dhildenb
^ permalink raw reply
* Re: [PATCH v6 10/10] mm/memory_hotplug: Cleanup __remove_pages()
From: David Hildenbrand @ 2020-02-05 13:18 UTC (permalink / raw)
To: Segher Boessenkool
Cc: linux-s390, Michal Hocko, linux-ia64, Pavel Tatashin, linux-sh,
x86, linux-kernel, linux-mm, Wei Yang, Andrew Morton,
linuxppc-dev, Dan Williams, linux-arm-kernel, Oscar Salvador
In-Reply-To: <32e06c13-222c-4486-3914-df2807cf2a2b@redhat.com>
> I'm sorry to have to correct you again for some corner cases:
>
> ALIGN_UP(1, 4096) - 4096 = 0
>
> Again, not as easy as it seems ...
>
Eh, wait, I'm messing up things. Will double check :)
--
Thanks,
David / dhildenb
^ permalink raw reply
* Re: [PATCH v6 10/10] mm/memory_hotplug: Cleanup __remove_pages()
From: David Hildenbrand @ 2020-02-05 13:17 UTC (permalink / raw)
To: Segher Boessenkool
Cc: linux-s390, Michal Hocko, linux-ia64, Pavel Tatashin, linux-sh,
x86, linux-kernel, linux-mm, Wei Yang, Andrew Morton,
linuxppc-dev, Dan Williams, linux-arm-kernel, Oscar Salvador
In-Reply-To: <20200205125149.GS22482@gate.crashing.org>
On 05.02.20 13:51, Segher Boessenkool wrote:
> On Tue, Feb 04, 2020 at 02:38:51PM +0100, David Hildenbrand wrote:
>> On 04.02.20 14:13, Segher Boessenkool wrote:
>>> On Tue, Feb 04, 2020 at 01:41:06PM +0100, David Hildenbrand wrote:
>>>> It's a pattern commonly used in compilers and emulators to calculate the
>>>> number of bytes to the next block/alignment. (we're missing a macro
>>>> (like we have ALIGN_UP/IS_ALIGNED) for that - but it's hard to come up
>>>> with a good name (e.g., SIZE_TO_NEXT_ALIGN) .
>
>>> You can just write the easy to understand
>>>
>>> ... ALIGN_UP(x) - x ...
>>
>> you mean
>>
>> ALIGN_UP(x, PAGES_PER_SECTION) - x
>>
>> but ...
>>
>>> which is better *without* having a separate name. Does that not
>>> generate good machine code for you?
>>
>> 1. There is no ALIGN_UP. "SECTION_ALIGN_UP(x) - x" would be possible
>
> Erm, you started it ;-)
Yeah, I was thinking in the wrong code base :)
>
>> 2. It would be wrong if x is already aligned.
>>
>> e.g., let's use 4096 for simplicity as we all know that value by heart
>> (for both x and the block size).
>>
>> a) -(4096 | -4096) -> 4096
>>
>> b) #define ALIGN_UP(x, a) ((x + a - 1) & -(a))
>>
>> ALIGN_UP(4096, 4096) - 4096 -> 0
>>
>> Not as easy as it seems ...
>
> If you always want to return a number >= 1, it it simply
> ALIGN_UP(x + 1) - x
I'm sorry to have to correct you again for some corner cases:
ALIGN_UP(1, 4096) - 4096 = 0
Again, not as easy as it seems ...
--
Thanks,
David / dhildenb
^ permalink raw reply
* Re: Latest Git kernel: avahi-daemon[2410]: ioctl(): Inappropriate ioctl for device
From: Christian Zigotzky @ 2020-02-05 13:03 UTC (permalink / raw)
To: Jakub Kicinski
Cc: DTML, Darren Stevens, mad skateman, Linux Kernel Mailing List,
linuxppc-dev, contact@a-eon.com, R.T.Dickinson,
netdev@vger.kernel.org, Christoph Hellwig
In-Reply-To: <20200203095325.24c3ab1c@cakuba.hsd1.ca.comcast.net>
On 03 February 2020 at 6:53 pm, Jakub Kicinski wrote:
> On Sun, 2 Feb 2020 16:02:18 +0100, Christian Zigotzky wrote:
>> On 02 February 2020 at 09:19 am, Christophe Leroy wrote:
>>> Hello,
>>>
>>> Le 02/02/2020 à 01:08, Christian Zigotzky a écrit :
>>>> Hello,
>>>>
>>>> We regularly compile and test Linux kernels every day during the
>>>> merge window. Since Thursday we have very high CPU loads because of
>>>> the avahi daemon on our desktop Linux systems (Ubuntu, Debian etc).
>>>>
>>>> Error message: avahi-daemon[2410]: ioctl(): Inappropriate ioctl for
>>>> device
>>> Do you know which ioctl, on which device ?
>>> Can you take a trace of running avahi-daemon with 'strace' ?
>>>
>>> Can you bisect ?
>>>
>>> Christophe
>> Hi Christophe,
>> Hi All,
>>
>> I figured out that the avahi-daemon has a problem with the IPv6 address
>> of a network interface since the Git kernel from Thursday. (Log attached)
>> This generates high CPU usage because the avahi-daemon tries to access
>> the IPv6 address again and again and thereby it produces a lot of log
>> messages.
>>
>> We figured out that the networking updates aren't responsible for this
>> issue because we created a test kernel on Wednesday. The issue is
>> somewhere in the commits from Wednesday night to Thursday (CET).
> FWIW Thursday is when the latest networking pull came in, so could well
> be networking related..
>
>> Please compile the latest Git kernel and test it with a desktop linux
>> distribution for example Ubuntu. In my point of view there are many
>> desktop machines affected. Many server systems don't use the avahi
>> daemon so they aren't affected.
>>
>> It's possible to deactivate the access to the IPv6 address with the
>> following line in the file "/etc/avahi/avahi-daemon.conf":
>>
>> use-ipv6=no
>>
>> After a reboot the CPU usage is normal again. This is only a temporary
>> solution.
>>
>> Unfortunately I don't have the time for bisecting next week. I have a
>> lot of other work to do. In my point of view it is very important that
>> you also compile the latest Git kernels. Then you will see the issue and
>> then you have a better possibility to fix the issue.
Hi All,
The issue still exist in the latest Git kernel. It's a PowerPC issue. I
compiled the latest Git kernel on a PC today and there aren't any issues
with the avahi daemon. Another Power Mac user reported the same issue on
his G5. I tested with the AmigaOne X1000 and X5000 in the last days.
I bisected today but I think the result isn't correct because it founds
the other problem with ordering of PCSCSI definition in esp_rev enum. I
don't know how to bisect if there is another issue at the same time.
Maybe "git bisect skip"?
2086faae3c55a652cfbd369e18ecdb703aacc493 is the first bad commit
commit 2086faae3c55a652cfbd369e18ecdb703aacc493
Author: Kars de Jong <jongk@linux-m68k.org>
Date: Tue Nov 19 21:20:20 2019 +0100
scsi: esp_scsi: Correct ordering of PCSCSI definition in esp_rev enum
The order of the definitions in the esp_rev enum is important. The
values
are used in comparisons for chip features.
Add a comment to the enum explaining this.
Also, the actual values for the enum fields are irrelevant, so
remove the
explicit values (suggested by Geert Uytterhoeven). This makes
adding a new
field in the middle of the enum easier.
Finally, move the PCSCSI definition to the right place in the enum.
In its
previous location, at the end of the enum, the wrong values are
written to
the CONFIG3 register when used with FAST-SCSI targets.
Link:
https://lore.kernel.org/r/20191119202021.28720-2-jongk@linux-m68k.org
Signed-off-by: Kars de Jong <jongk@linux-m68k.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
:040000 040000 cdc128596e33fb60406b5de9b17b79623c187c1a
48ceab06439f95285e8b30181e75f9a68c25fcb5 M drivers
Cheers,
Christian
^ permalink raw reply
* Re: [PATCH v6 10/10] mm/memory_hotplug: Cleanup __remove_pages()
From: Segher Boessenkool @ 2020-02-05 12:51 UTC (permalink / raw)
To: David Hildenbrand
Cc: linux-s390, Michal Hocko, linux-ia64, Pavel Tatashin, linux-sh,
x86, linux-kernel, linux-mm, Wei Yang, Andrew Morton,
linuxppc-dev, Dan Williams, linux-arm-kernel, Oscar Salvador
In-Reply-To: <0e2f700c-b01b-8c16-99c2-2648967fc203@redhat.com>
On Tue, Feb 04, 2020 at 02:38:51PM +0100, David Hildenbrand wrote:
> On 04.02.20 14:13, Segher Boessenkool wrote:
> > On Tue, Feb 04, 2020 at 01:41:06PM +0100, David Hildenbrand wrote:
> >> It's a pattern commonly used in compilers and emulators to calculate the
> >> number of bytes to the next block/alignment. (we're missing a macro
> >> (like we have ALIGN_UP/IS_ALIGNED) for that - but it's hard to come up
> >> with a good name (e.g., SIZE_TO_NEXT_ALIGN) .
> > You can just write the easy to understand
> >
> > ... ALIGN_UP(x) - x ...
>
> you mean
>
> ALIGN_UP(x, PAGES_PER_SECTION) - x
>
> but ...
>
> > which is better *without* having a separate name. Does that not
> > generate good machine code for you?
>
> 1. There is no ALIGN_UP. "SECTION_ALIGN_UP(x) - x" would be possible
Erm, you started it ;-)
> 2. It would be wrong if x is already aligned.
>
> e.g., let's use 4096 for simplicity as we all know that value by heart
> (for both x and the block size).
>
> a) -(4096 | -4096) -> 4096
>
> b) #define ALIGN_UP(x, a) ((x + a - 1) & -(a))
>
> ALIGN_UP(4096, 4096) - 4096 -> 0
>
> Not as easy as it seems ...
If you always want to return a number >= 1, it it simply
ALIGN_UP(x + 1) - x
(and replace 1 by any other minimum size required). This *also* is
easy to read, without having to have any details (and quirks :-/ )
of those utility functions memorised.
Segher
^ permalink raw reply
* Re: [PATCH v6 08/10] mm/memory_hotplug: Don't check for "all holes" in shrink_zone_span()
From: Baoquan He @ 2020-02-05 12:43 UTC (permalink / raw)
To: David Hildenbrand
Cc: linux-s390, Michal Hocko, linux-ia64, Pavel Tatashin, linux-sh,
x86, linux-kernel, linux-mm, Wei Yang, Andrew Morton,
linuxppc-dev, Dan Williams, linux-arm-kernel, Oscar Salvador
In-Reply-To: <e0006cc4-d448-89c6-38c0-51da7fc08715@redhat.com>
On 02/04/20 at 03:42pm, David Hildenbrand wrote:
> On 04.02.20 15:25, Baoquan He wrote:
> > On 10/06/19 at 10:56am, David Hildenbrand wrote:
> >> If we have holes, the holes will automatically get detected and removed
> >> once we remove the next bigger/smaller section. The extra checks can
> >> go.
> >>
> >> Cc: Andrew Morton <akpm@linux-foundation.org>
> >> Cc: Oscar Salvador <osalvador@suse.de>
> >> Cc: Michal Hocko <mhocko@suse.com>
> >> Cc: David Hildenbrand <david@redhat.com>
> >> Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
> >> Cc: Dan Williams <dan.j.williams@intel.com>
> >> Cc: Wei Yang <richardw.yang@linux.intel.com>
> >> Signed-off-by: David Hildenbrand <david@redhat.com>
> >> ---
> >> mm/memory_hotplug.c | 34 +++++++---------------------------
> >> 1 file changed, 7 insertions(+), 27 deletions(-)
> >>
> >> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> >> index f294918f7211..8dafa1ba8d9f 100644
> >> --- a/mm/memory_hotplug.c
> >> +++ b/mm/memory_hotplug.c
> >> @@ -393,6 +393,9 @@ static void shrink_zone_span(struct zone *zone, unsigned long start_pfn,
> >> if (pfn) {
> >> zone->zone_start_pfn = pfn;
> >> zone->spanned_pages = zone_end_pfn - pfn;
> >> + } else {
> >> + zone->zone_start_pfn = 0;
> >> + zone->spanned_pages = 0;
> >> }
> >> } else if (zone_end_pfn == end_pfn) {
> >> /*
> >> @@ -405,34 +408,11 @@ static void shrink_zone_span(struct zone *zone, unsigned long start_pfn,
> >> start_pfn);
> >> if (pfn)
> >> zone->spanned_pages = pfn - zone_start_pfn + 1;
> >> + else {
> >> + zone->zone_start_pfn = 0;
> >> + zone->spanned_pages = 0;
> >
> > Thinking in which case (zone_start_pfn != start_pfn) and it comes here.
>
> Could only happen in case the zone_start_pfn would have been "out of the
> zone already". If you ask me: unlikely :)
Yeah, I also think it's unlikely to come here.
The 'if (zone_start_pfn == start_pfn)' checking also covers the case
(zone_start_pfn == start_pfn && zone_end_pfn == end_pfn). So this
zone_start_pfn/spanned_pages resetting can be removed to avoid
confusion.
^ permalink raw reply
* [PATCH] powerpc/legacy_serial: Use early_ioremap()
From: Christophe Leroy @ 2020-02-05 12:03 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman
Cc: linuxppc-dev, linux-kernel
[ 0.000000] ioremap() called early from find_legacy_serial_ports+0x3cc/0x474. Use early_ioremap() instead
find_legacy_serial_ports() is called early from setup_arch(), before
paging_init(). vmalloc is not available yet, ioremap shouldn't be
used that early.
Use early_ioremap() and switch to a regular ioremap() later.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
arch/powerpc/kernel/legacy_serial.c | 33 +++++++++++++++++++++++++----
1 file changed, 29 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/kernel/legacy_serial.c b/arch/powerpc/kernel/legacy_serial.c
index f061e06e9f51..8b2c1a8553a0 100644
--- a/arch/powerpc/kernel/legacy_serial.c
+++ b/arch/powerpc/kernel/legacy_serial.c
@@ -15,6 +15,7 @@
#include <asm/udbg.h>
#include <asm/pci-bridge.h>
#include <asm/ppc-pci.h>
+#include <asm/early_ioremap.h>
#undef DEBUG
@@ -34,6 +35,7 @@ static struct legacy_serial_info {
unsigned int clock;
int irq_check_parent;
phys_addr_t taddr;
+ void __iomem *early_addr;
} legacy_serial_infos[MAX_LEGACY_SERIAL_PORTS];
static const struct of_device_id legacy_serial_parents[] __initconst = {
@@ -325,17 +327,16 @@ static void __init setup_legacy_serial_console(int console)
{
struct legacy_serial_info *info = &legacy_serial_infos[console];
struct plat_serial8250_port *port = &legacy_serial_ports[console];
- void __iomem *addr;
unsigned int stride;
stride = 1 << port->regshift;
/* Check if a translated MMIO address has been found */
if (info->taddr) {
- addr = ioremap(info->taddr, 0x1000);
- if (addr == NULL)
+ info->early_addr = early_ioremap(info->taddr, 0x1000);
+ if (info->early_addr == NULL)
return;
- udbg_uart_init_mmio(addr, stride);
+ udbg_uart_init_mmio(info->early_addr, stride);
} else {
/* Check if it's PIO and we support untranslated PIO */
if (port->iotype == UPIO_PORT && isa_io_special)
@@ -353,6 +354,30 @@ static void __init setup_legacy_serial_console(int console)
udbg_uart_setup(info->speed, info->clock);
}
+static int __init ioremap_legacy_serial_console(void)
+{
+ struct legacy_serial_info *info = &legacy_serial_infos[legacy_serial_console];
+ struct plat_serial8250_port *port = &legacy_serial_ports[legacy_serial_console];
+ void __iomem *vaddr;
+
+ if (legacy_serial_console < 0)
+ return 0;
+
+ if (!info->early_addr)
+ return 0;
+
+ vaddr = ioremap(info->taddr, 0x1000);
+ if (WARN_ON(!vaddr))
+ return -ENOMEM;
+
+ udbg_uart_init_mmio(vaddr, 1 << port->regshift);
+ early_iounmap(info->early_addr, 0x1000);
+ info->early_addr = NULL;
+
+ return 0;
+}
+early_initcall(ioremap_legacy_serial_console);
+
/*
* This is called very early, as part of setup_system() or eventually
* setup_arch(), basically before anything else in this file. This function
--
2.25.0
^ permalink raw reply related
* Re: [PATCH v6 10/10] mm/memory_hotplug: Cleanup __remove_pages()
From: Wei Yang @ 2020-02-05 11:48 UTC (permalink / raw)
To: David Hildenbrand
Cc: linux-s390, Michal Hocko, linux-ia64, Pavel Tatashin, linux-sh,
x86, linux-kernel, linux-mm, Wei Yang, Andrew Morton,
linuxppc-dev, Dan Williams, linux-arm-kernel, Oscar Salvador
In-Reply-To: <20191006085646.5768-11-david@redhat.com>
On Sun, Oct 06, 2019 at 10:56:46AM +0200, David Hildenbrand wrote:
>Let's drop the basically unused section stuff and simplify.
>
>Also, let's use a shorter variant to calculate the number of pages to
>the next section boundary.
>
>Cc: Andrew Morton <akpm@linux-foundation.org>
>Cc: Oscar Salvador <osalvador@suse.de>
>Cc: Michal Hocko <mhocko@suse.com>
>Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
>Cc: Dan Williams <dan.j.williams@intel.com>
>Cc: Wei Yang <richardw.yang@linux.intel.com>
>Signed-off-by: David Hildenbrand <david@redhat.com>
Finally understand the code.
Reviewed-by: Wei Yang <richardw.yang@linux.intel.com>
--
Wei Yang
Help you, Help me
^ permalink raw reply
* [PATCH V13] mm/debug: Add tests validating architecture page table helpers
From: Anshuman Khandual @ 2020-02-05 10:14 UTC (permalink / raw)
To: linux-mm
Cc: Mark Rutland, uclinux-h8-devel, linux-ia64, linux-sh,
Peter Zijlstra, James Hogan, Tetsuo Handa, Heiko Carstens,
Michal Hocko, Dave Hansen, Paul Mackerras, sparclinux,
linux-hexagon, linux-riscv, Thomas Gleixner, linux-s390,
linux-c6x-dev, Yoshinori Sato, Max Filippov, x86,
Russell King - ARM Linux, Matthew Wilcox, Steven Price,
Jason Gunthorpe, Geert Uytterhoeven, Gerald Schaefer, Mark Salter,
Matt Turner, linux-snps-arc, linux-arm-kernel, Ingo Molnar,
linux-xtensa, Kees Cook, Anshuman Khandual, Masahiro Yamada,
linux-alpha, Aurelien Jacquiot, linux-m68k, Mark Brown,
Ivan Kokshaysky, Paul Walmsley, Kirill A . Shutemov, Dan Williams,
Guan Xuetao, Vlastimil Babka, Richard Henderson, Chris Zankel,
Michal Simek, Brian Cain, Ard Biesheuvel, Greg Kroah-Hartman,
linux-mips, Ralf Baechle, linux-kernel, Paul Burton,
Mike Rapoport, Palmer Dabbelt, Vineet Gupta, Martin Schwidefsky,
Qian Cai, Andrew Morton, linuxppc-dev, David S. Miller
This adds tests which will validate architecture page table helpers and
other accessors in their compliance with expected generic MM semantics.
This will help various architectures in validating changes to existing
page table helpers or addition of new ones.
This test covers basic page table entry transformations including but not
limited to old, young, dirty, clean, write, write protect etc at various
level along with populating intermediate entries with next page table page
and validating them.
Test page table pages are allocated from system memory with required size
and alignments. The mapped pfns at page table levels are derived from a
real pfn representing a valid kernel text symbol. This test gets called
inside kernel_init() right after async_synchronize_full().
This test gets built and run when CONFIG_DEBUG_VM_PGTABLE is selected. Any
architecture, which is willing to subscribe this test will need to select
ARCH_HAS_DEBUG_VM_PGTABLE. For now this is limited to arc, arm64, x86, s390
and ppc32 platforms where the test is known to build and run successfully.
Going forward, other architectures too can subscribe the test after fixing
any build or runtime problems with their page table helpers. Meanwhile for
better platform coverage, the test can also be enabled with CONFIG_EXPERT
even without ARCH_HAS_DEBUG_VM_PGTABLE.
Folks interested in making sure that a given platform's page table helpers
conform to expected generic MM semantics should enable the above config
which will just trigger this test during boot. Any non conformity here will
be reported as an warning which would need to be fixed. This test will help
catch any changes to the agreed upon semantics expected from generic MM and
enable platforms to accommodate it thereafter.
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Steven Price <Steven.Price@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Russell King - ARM Linux <linux@armlinux.org.uk>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Aurelien Jacquiot <jacquiot.aurelien@gmail.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Qian Cai <cai@lca.pw>
Cc: linux-alpha@vger.kernel.org
Cc: linux-c6x-dev@linux-c6x.org
Cc: uclinux-h8-devel@lists.sourceforge.jp
Cc: linux-hexagon@vger.kernel.org
Cc: linux-m68k@lists.linux-m68k.org
Cc: linux-riscv@lists.infradead.org
Cc: linux-xtensa@linux-xtensa.org
Cc: linux-snps-arc@lists.infradead.org
Cc: linux-mips@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-ia64@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-s390@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: sparclinux@vger.kernel.org
Cc: x86@kernel.org
Cc: linux-kernel@vger.kernel.org
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> # s390
Tested-by: Christophe Leroy <christophe.leroy@c-s.fr> # ppc32
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
This adds a test validation for architecture exported page table helpers.
Patch adds basic transformation tests at various levels of the page table.
This test was originally suggested by Catalin during arm64 THP migration
RFC discussion earlier. Going forward it can include more specific tests
with respect to various generic MM functions like THP, HugeTLB etc and
platform specific tests.
https://lore.kernel.org/linux-mm/20190628102003.GA56463@arrakis.emea.arm.com/
Needs to be applied on linux V5.5
Changes in V13:
- Subscribed s390 platform and updated debug-vm-pgtable/arch-support.txt per Gerald
- Dropped keyword 'extern' from debug_vm_pgtable() declaration per Christophe
- Moved debug_vm_pgtable() declarations to <linux/mmdebug.h> per Christophe
- Moved debug_vm_pgtable() call site into kernel_init() per Christophe
- Changed CONFIG_DEBUG_VM_PGTABLE rules per Christophe
- Updated commit to include new supported platforms and changed config selection
Changes in V12: (https://patchwork.kernel.org/project/linux-mm/list/?series=233905)
- Replaced __mmdrop() with mmdrop()
- Enable ARCH_HAS_DEBUG_VM_PGTABLE on X86 for non CONFIG_X86_PAE platforms as the
test procedure interfere with pre-allocated PMDs attached to the PGD resulting
in runtime failures with VM_BUG_ON()
Changes in V11: (https://patchwork.kernel.org/project/linux-mm/list/?series=221135)
- Rebased the patch on V5.4
Changes in V10: (https://patchwork.kernel.org/project/linux-mm/list/?series=205529)
- Always enable DEBUG_VM_PGTABLE when DEBUG_VM is enabled per Ingo
- Added tags from Ingo
Changes in V9: (https://patchwork.kernel.org/project/linux-mm/list/?series=201429)
- Changed feature support enumeration for powerpc platforms per Christophe
- Changed config wrapper for basic_[pmd|pud]_tests() to enable ARC platform
- Enabled the test on ARC platform
Changes in V8: (https://patchwork.kernel.org/project/linux-mm/list/?series=194297)
- Enabled ARCH_HAS_DEBUG_VM_PGTABLE on PPC32 platform per Christophe
- Updated feature documentation as DEBUG_VM_PGTABLE is now enabled on PPC32 platform
- Moved ARCH_HAS_DEBUG_VM_PGTABLE earlier to indent it with DEBUG_VM per Christophe
- Added an information message in debug_vm_pgtable() per Christophe
- Dropped random_vaddr boundary condition checks per Christophe and Qian
- Replaced virt_addr_valid() check with pfn_valid() check in debug_vm_pgtable()
- Slightly changed pr_fmt(fmt) information
Changes in V7: (https://patchwork.kernel.org/project/linux-mm/list/?series=193051)
- Memory allocation and free routines for mapped pages have been droped
- Mapped pfns are derived from standard kernel text symbol per Matthew
- Moved debug_vm_pgtaable() after page_alloc_init_late() per Michal and Qian
- Updated the commit message per Michal
- Updated W=1 GCC warning problem on x86 per Qian Cai
- Addition of new alloc_contig_pages() helper has been submitted separately
Changes in V6: (https://patchwork.kernel.org/project/linux-mm/list/?series=187589)
- Moved alloc_gigantic_page_order() into mm/page_alloc.c per Michal
- Moved alloc_gigantic_page_order() within CONFIG_CONTIG_ALLOC in the test
- Folded Andrew's include/asm-generic/pgtable.h fix into the test patch 2/2
Changes in V5: (https://patchwork.kernel.org/project/linux-mm/list/?series=185991)
- Redefined and moved X86 mm_p4d_folded() into a different header per Kirill/Ingo
- Updated the config option comment per Ingo and dropped 'kernel module' reference
- Updated the commit message and dropped 'kernel module' reference
- Changed DEBUG_ARCH_PGTABLE_TEST into DEBUG_VM_PGTABLE per Ingo
- Moved config option from mm/Kconfig.debug into lib/Kconfig.debug
- Renamed core test function arch_pgtable_tests() as debug_vm_pgtable()
- Renamed mm/arch_pgtable_test.c as mm/debug_vm_pgtable.c
- debug_vm_pgtable() gets called from kernel_init_freeable() after init_mm_internals()
- Added an entry in Documentation/features/debug/ per Ingo
- Enabled the test on arm64 and x86 platforms for now
Changes in V4: (https://patchwork.kernel.org/project/linux-mm/list/?series=183465)
- Disable DEBUG_ARCH_PGTABLE_TEST for ARM and IA64 platforms
Changes in V3: (https://lore.kernel.org/patchwork/project/lkml/list/?series=411216)
- Changed test trigger from module format into late_initcall()
- Marked all functions with __init to be freed after completion
- Changed all __PGTABLE_PXX_FOLDED checks as mm_pxx_folded()
- Folded in PPC32 fixes from Christophe
Changes in V2:
https://lore.kernel.org/linux-mm/1568268173-31302-1-git-send-email-anshuman.khandual@arm.com/T/#t
- Fixed small typo error in MODULE_DESCRIPTION()
- Fixed m64k build problems for lvalue concerns in pmd_xxx_tests()
- Fixed dynamic page table level folding problems on x86 as per Kirril
- Fixed second pointers during pxx_populate_tests() per Kirill and Gerald
- Allocate and free pte table with pte_alloc_one/pte_free per Kirill
- Modified pxx_clear_tests() to accommodate s390 lower 12 bits situation
- Changed RANDOM_NZVALUE value from 0xbe to 0xff
- Changed allocation, usage, free sequence for saved_ptep
- Renamed VMA_FLAGS as VMFLAGS
- Implemented a new method for random vaddr generation
- Implemented some other cleanups
- Dropped extern reference to mm_alloc()
- Created and exported new alloc_gigantic_page_order()
- Dropped the custom allocator and used new alloc_gigantic_page_order()
Changes in V1:
https://lore.kernel.org/linux-mm/1567497706-8649-1-git-send-email-anshuman.khandual@arm.com/
- Added fallback mechanism for PMD aligned memory allocation failure
Changes in RFC V2:
https://lore.kernel.org/linux-mm/1565335998-22553-1-git-send-email-anshuman.khandual@arm.com/T/#u
- Moved test module and it's config from lib/ to mm/
- Renamed config TEST_ARCH_PGTABLE as DEBUG_ARCH_PGTABLE_TEST
- Renamed file from test_arch_pgtable.c to arch_pgtable_test.c
- Added relevant MODULE_DESCRIPTION() and MODULE_AUTHOR() details
- Dropped loadable module config option
- Basic tests now use memory blocks with required size and alignment
- PUD aligned memory block gets allocated with alloc_contig_range()
- If PUD aligned memory could not be allocated it falls back on PMD aligned
memory block from page allocator and pud_* tests are skipped
- Clear and populate tests now operate on real in memory page table entries
- Dummy mm_struct gets allocated with mm_alloc()
- Dummy page table entries get allocated with [pud|pmd|pte]_alloc_[map]()
- Simplified [p4d|pgd]_basic_tests(), now has random values in the entries
Original RFC V1:
https://lore.kernel.org/linux-mm/1564037723-26676-1-git-send-email-anshuman.khandual@arm.com/
.../debug/debug-vm-pgtable/arch-support.txt | 35 ++
arch/arc/Kconfig | 1 +
arch/arm64/Kconfig | 1 +
arch/powerpc/Kconfig | 1 +
arch/s390/Kconfig | 1 +
arch/x86/Kconfig | 1 +
arch/x86/include/asm/pgtable_64.h | 6 +
include/linux/mmdebug.h | 5 +
init/main.c | 2 +
lib/Kconfig.debug | 22 +
mm/Makefile | 1 +
mm/debug_vm_pgtable.c | 388 ++++++++++++++++++
12 files changed, 464 insertions(+)
create mode 100644 Documentation/features/debug/debug-vm-pgtable/arch-support.txt
create mode 100644 mm/debug_vm_pgtable.c
diff --git a/Documentation/features/debug/debug-vm-pgtable/arch-support.txt b/Documentation/features/debug/debug-vm-pgtable/arch-support.txt
new file mode 100644
index 000000000000..64d0f9b15c49
--- /dev/null
+++ b/Documentation/features/debug/debug-vm-pgtable/arch-support.txt
@@ -0,0 +1,35 @@
+#
+# Feature name: debug-vm-pgtable
+# Kconfig: ARCH_HAS_DEBUG_VM_PGTABLE
+# description: arch supports pgtable tests for semantics compliance
+#
+ -----------------------
+ | arch |status|
+ -----------------------
+ | alpha: | TODO |
+ | arc: | ok |
+ | arm: | TODO |
+ | arm64: | ok |
+ | c6x: | TODO |
+ | csky: | TODO |
+ | h8300: | TODO |
+ | hexagon: | TODO |
+ | ia64: | TODO |
+ | m68k: | TODO |
+ | microblaze: | TODO |
+ | mips: | TODO |
+ | nds32: | TODO |
+ | nios2: | TODO |
+ | openrisc: | TODO |
+ | parisc: | TODO |
+ | powerpc/32: | ok |
+ | powerpc/64: | TODO |
+ | riscv: | TODO |
+ | s390: | ok |
+ | sh: | TODO |
+ | sparc: | TODO |
+ | um: | TODO |
+ | unicore32: | TODO |
+ | x86: | ok |
+ | xtensa: | TODO |
+ -----------------------
diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index 26108ea785c2..6a76f3b609b2 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -6,6 +6,7 @@
config ARC
def_bool y
select ARC_TIMERS
+ select ARCH_HAS_DEBUG_VM_PGTABLE
select ARCH_HAS_DMA_PREP_COHERENT
select ARCH_HAS_PTE_SPECIAL
select ARCH_HAS_SETUP_DMA_OPS
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index e688dfad0b72..876c9a672db1 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -11,6 +11,7 @@ config ARM64
select ACPI_PPTT if ACPI
select ARCH_CLOCKSOURCE_DATA
select ARCH_HAS_DEBUG_VIRTUAL
+ select ARCH_HAS_DEBUG_VM_PGTABLE
select ARCH_HAS_DEVMEM_IS_ALLOWED
select ARCH_HAS_DMA_PREP_COHERENT
select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index e2a412113359..e229e2a86518 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -120,6 +120,7 @@ config PPC
#
select ARCH_32BIT_OFF_T if PPC32
select ARCH_HAS_DEBUG_VIRTUAL
+ select ARCH_HAS_DEBUG_VM_PGTABLE if PPC32
select ARCH_HAS_DEVMEM_IS_ALLOWED
select ARCH_HAS_ELF_RANDOMIZE
select ARCH_HAS_FORTIFY_SOURCE
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index bc88841d335d..2ea962ead27e 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -59,6 +59,7 @@ config KASAN_SHADOW_OFFSET
config S390
def_bool y
select ARCH_BINFMT_ELF_STATE
+ select ARCH_HAS_DEBUG_VM_PGTABLE
select ARCH_HAS_DEVMEM_IS_ALLOWED
select ARCH_HAS_ELF_RANDOMIZE
select ARCH_HAS_FORTIFY_SOURCE
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 5e8949953660..218536a4581d 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -61,6 +61,7 @@ config X86
select ARCH_CLOCKSOURCE_INIT
select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
select ARCH_HAS_DEBUG_VIRTUAL
+ select ARCH_HAS_DEBUG_VM_PGTABLE if !X86_PAE
select ARCH_HAS_DEVMEM_IS_ALLOWED
select ARCH_HAS_ELF_RANDOMIZE
select ARCH_HAS_FAST_MULTIPLIER
diff --git a/arch/x86/include/asm/pgtable_64.h b/arch/x86/include/asm/pgtable_64.h
index 0b6c4042942a..fb0e76d254b3 100644
--- a/arch/x86/include/asm/pgtable_64.h
+++ b/arch/x86/include/asm/pgtable_64.h
@@ -53,6 +53,12 @@ static inline void sync_initial_page_table(void) { }
struct mm_struct;
+#define mm_p4d_folded mm_p4d_folded
+static inline bool mm_p4d_folded(struct mm_struct *mm)
+{
+ return !pgtable_l5_enabled();
+}
+
void set_pte_vaddr_p4d(p4d_t *p4d_page, unsigned long vaddr, pte_t new_pte);
void set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte);
diff --git a/include/linux/mmdebug.h b/include/linux/mmdebug.h
index 2ad72d2c8cc5..5339aa14b749 100644
--- a/include/linux/mmdebug.h
+++ b/include/linux/mmdebug.h
@@ -64,4 +64,9 @@ void dump_mm(const struct mm_struct *mm);
#define VM_BUG_ON_PGFLAGS(cond, page) BUILD_BUG_ON_INVALID(cond)
#endif
+#ifdef CONFIG_DEBUG_VM_PGTABLE
+void debug_vm_pgtable(void);
+#else
+static inline void debug_vm_pgtable(void) { }
+#endif
#endif
diff --git a/init/main.c b/init/main.c
index da1bc0b60a7d..e2999239bb8c 100644
--- a/init/main.c
+++ b/init/main.c
@@ -93,6 +93,7 @@
#include <linux/rodata_test.h>
#include <linux/jump_label.h>
#include <linux/mem_encrypt.h>
+#include <linux/mmdebug.h>
#include <asm/io.h>
#include <asm/bugs.h>
@@ -1110,6 +1111,7 @@ static int __ref kernel_init(void *unused)
kernel_init_freeable();
/* need to finish all async __init code before freeing the memory */
async_synchronize_full();
+ debug_vm_pgtable();
ftrace_free_init_mem();
free_initmem();
mark_readonly();
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 5ffe144c9794..64c80f7af904 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -653,6 +653,12 @@ config SCHED_STACK_END_CHECK
data corruption or a sporadic crash at a later stage once the region
is examined. The runtime overhead introduced is minimal.
+config ARCH_HAS_DEBUG_VM_PGTABLE
+ bool
+ help
+ An architecture should select this when it can successfully
+ build and run DEBUG_VM_PGTABLE.
+
config DEBUG_VM
bool "Debug VM"
depends on DEBUG_KERNEL
@@ -688,6 +694,22 @@ config DEBUG_VM_PGFLAGS
If unsure, say N.
+config DEBUG_VM_PGTABLE
+ bool "Debug arch page table for semantics compliance"
+ depends on MMU
+ depends on ARCH_HAS_DEBUG_VM_PGTABLE || EXPERT
+ default n if !ARCH_HAS_DEBUG_VM_PGTABLE
+ default y if DEBUG_VM
+ help
+ This option provides a debug method which can be used to test
+ architecture page table helper functions on various platforms in
+ verifying if they comply with expected generic MM semantics. This
+ will help architecture code in making sure that any changes or
+ new additions of these helpers still conform to expected
+ semantics of the generic MM.
+
+ If unsure, say N.
+
config ARCH_HAS_DEBUG_VIRTUAL
bool
diff --git a/mm/Makefile b/mm/Makefile
index 1937cc251883..eba423a26b19 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -86,6 +86,7 @@ obj-$(CONFIG_HWPOISON_INJECT) += hwpoison-inject.o
obj-$(CONFIG_DEBUG_KMEMLEAK) += kmemleak.o
obj-$(CONFIG_DEBUG_KMEMLEAK_TEST) += kmemleak-test.o
obj-$(CONFIG_DEBUG_RODATA_TEST) += rodata_test.o
+obj-$(CONFIG_DEBUG_VM_PGTABLE) += debug_vm_pgtable.o
obj-$(CONFIG_PAGE_OWNER) += page_owner.o
obj-$(CONFIG_CLEANCACHE) += cleancache.o
obj-$(CONFIG_MEMORY_ISOLATION) += page_isolation.o
diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
new file mode 100644
index 000000000000..0f37f32d15f1
--- /dev/null
+++ b/mm/debug_vm_pgtable.c
@@ -0,0 +1,388 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * This kernel test validates architecture page table helpers and
+ * accessors and helps in verifying their continued compliance with
+ * expected generic MM semantics.
+ *
+ * Copyright (C) 2019 ARM Ltd.
+ *
+ * Author: Anshuman Khandual <anshuman.khandual@arm.com>
+ */
+#define pr_fmt(fmt) "debug_vm_pgtable: %s: " fmt, __func__
+
+#include <linux/gfp.h>
+#include <linux/highmem.h>
+#include <linux/hugetlb.h>
+#include <linux/kernel.h>
+#include <linux/kconfig.h>
+#include <linux/mm.h>
+#include <linux/mman.h>
+#include <linux/mm_types.h>
+#include <linux/module.h>
+#include <linux/pfn_t.h>
+#include <linux/printk.h>
+#include <linux/random.h>
+#include <linux/spinlock.h>
+#include <linux/swap.h>
+#include <linux/swapops.h>
+#include <linux/start_kernel.h>
+#include <linux/sched/mm.h>
+#include <asm/pgalloc.h>
+#include <asm/pgtable.h>
+
+/*
+ * Basic operations
+ *
+ * mkold(entry) = An old and not a young entry
+ * mkyoung(entry) = A young and not an old entry
+ * mkdirty(entry) = A dirty and not a clean entry
+ * mkclean(entry) = A clean and not a dirty entry
+ * mkwrite(entry) = A write and not a write protected entry
+ * wrprotect(entry) = A write protected and not a write entry
+ * pxx_bad(entry) = A mapped and non-table entry
+ * pxx_same(entry1, entry2) = Both entries hold the exact same value
+ */
+#define VMFLAGS (VM_READ|VM_WRITE|VM_EXEC)
+
+/*
+ * On s390 platform, the lower 12 bits are used to identify given page table
+ * entry type and for other arch specific requirements. But these bits might
+ * affect the ability to clear entries with pxx_clear(). So while loading up
+ * the entries skip all lower 12 bits in order to accommodate s390 platform.
+ * It does not have affect any other platform.
+ */
+#define RANDOM_ORVALUE (0xfffffffffffff000UL)
+#define RANDOM_NZVALUE (0xff)
+
+static void __init pte_basic_tests(unsigned long pfn, pgprot_t prot)
+{
+ pte_t pte = pfn_pte(pfn, prot);
+
+ WARN_ON(!pte_same(pte, pte));
+ WARN_ON(!pte_young(pte_mkyoung(pte)));
+ WARN_ON(!pte_dirty(pte_mkdirty(pte)));
+ WARN_ON(!pte_write(pte_mkwrite(pte)));
+ WARN_ON(pte_young(pte_mkold(pte)));
+ WARN_ON(pte_dirty(pte_mkclean(pte)));
+ WARN_ON(pte_write(pte_wrprotect(pte)));
+}
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+static void __init pmd_basic_tests(unsigned long pfn, pgprot_t prot)
+{
+ pmd_t pmd = pfn_pmd(pfn, prot);
+
+ WARN_ON(!pmd_same(pmd, pmd));
+ WARN_ON(!pmd_young(pmd_mkyoung(pmd)));
+ WARN_ON(!pmd_dirty(pmd_mkdirty(pmd)));
+ WARN_ON(!pmd_write(pmd_mkwrite(pmd)));
+ WARN_ON(pmd_young(pmd_mkold(pmd)));
+ WARN_ON(pmd_dirty(pmd_mkclean(pmd)));
+ WARN_ON(pmd_write(pmd_wrprotect(pmd)));
+ /*
+ * A huge page does not point to next level page table
+ * entry. Hence this must qualify as pmd_bad().
+ */
+ WARN_ON(!pmd_bad(pmd_mkhuge(pmd)));
+}
+
+#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
+static void __init pud_basic_tests(unsigned long pfn, pgprot_t prot)
+{
+ pud_t pud = pfn_pud(pfn, prot);
+
+ WARN_ON(!pud_same(pud, pud));
+ WARN_ON(!pud_young(pud_mkyoung(pud)));
+ WARN_ON(!pud_write(pud_mkwrite(pud)));
+ WARN_ON(pud_write(pud_wrprotect(pud)));
+ WARN_ON(pud_young(pud_mkold(pud)));
+
+ if (mm_pmd_folded(mm) || __is_defined(ARCH_HAS_4LEVEL_HACK))
+ return;
+
+ /*
+ * A huge page does not point to next level page table
+ * entry. Hence this must qualify as pud_bad().
+ */
+ WARN_ON(!pud_bad(pud_mkhuge(pud)));
+}
+#else
+static void __init pud_basic_tests(unsigned long pfn, pgprot_t prot) { }
+#endif
+#else
+static void __init pmd_basic_tests(unsigned long pfn, pgprot_t prot) { }
+static void __init pud_basic_tests(unsigned long pfn, pgprot_t prot) { }
+#endif
+
+static void __init p4d_basic_tests(unsigned long pfn, pgprot_t prot)
+{
+ p4d_t p4d;
+
+ memset(&p4d, RANDOM_NZVALUE, sizeof(p4d_t));
+ WARN_ON(!p4d_same(p4d, p4d));
+}
+
+static void __init pgd_basic_tests(unsigned long pfn, pgprot_t prot)
+{
+ pgd_t pgd;
+
+ memset(&pgd, RANDOM_NZVALUE, sizeof(pgd_t));
+ WARN_ON(!pgd_same(pgd, pgd));
+}
+
+#ifndef __ARCH_HAS_4LEVEL_HACK
+static void __init pud_clear_tests(struct mm_struct *mm, pud_t *pudp)
+{
+ pud_t pud = READ_ONCE(*pudp);
+
+ if (mm_pmd_folded(mm))
+ return;
+
+ pud = __pud(pud_val(pud) | RANDOM_ORVALUE);
+ WRITE_ONCE(*pudp, pud);
+ pud_clear(pudp);
+ pud = READ_ONCE(*pudp);
+ WARN_ON(!pud_none(pud));
+}
+
+static void __init pud_populate_tests(struct mm_struct *mm, pud_t *pudp,
+ pmd_t *pmdp)
+{
+ pud_t pud;
+
+ if (mm_pmd_folded(mm))
+ return;
+ /*
+ * This entry points to next level page table page.
+ * Hence this must not qualify as pud_bad().
+ */
+ pmd_clear(pmdp);
+ pud_clear(pudp);
+ pud_populate(mm, pudp, pmdp);
+ pud = READ_ONCE(*pudp);
+ WARN_ON(pud_bad(pud));
+}
+#else
+static void __init pud_clear_tests(struct mm_struct *mm, pud_t *pudp) { }
+static void __init pud_populate_tests(struct mm_struct *mm, pud_t *pudp,
+ pmd_t *pmdp)
+{
+}
+#endif
+
+#ifndef __ARCH_HAS_5LEVEL_HACK
+static void __init p4d_clear_tests(struct mm_struct *mm, p4d_t *p4dp)
+{
+ p4d_t p4d = READ_ONCE(*p4dp);
+
+ if (mm_pud_folded(mm))
+ return;
+
+ p4d = __p4d(p4d_val(p4d) | RANDOM_ORVALUE);
+ WRITE_ONCE(*p4dp, p4d);
+ p4d_clear(p4dp);
+ p4d = READ_ONCE(*p4dp);
+ WARN_ON(!p4d_none(p4d));
+}
+
+static void __init p4d_populate_tests(struct mm_struct *mm, p4d_t *p4dp,
+ pud_t *pudp)
+{
+ p4d_t p4d;
+
+ if (mm_pud_folded(mm))
+ return;
+
+ /*
+ * This entry points to next level page table page.
+ * Hence this must not qualify as p4d_bad().
+ */
+ pud_clear(pudp);
+ p4d_clear(p4dp);
+ p4d_populate(mm, p4dp, pudp);
+ p4d = READ_ONCE(*p4dp);
+ WARN_ON(p4d_bad(p4d));
+}
+
+static void __init pgd_clear_tests(struct mm_struct *mm, pgd_t *pgdp)
+{
+ pgd_t pgd = READ_ONCE(*pgdp);
+
+ if (mm_p4d_folded(mm))
+ return;
+
+ pgd = __pgd(pgd_val(pgd) | RANDOM_ORVALUE);
+ WRITE_ONCE(*pgdp, pgd);
+ pgd_clear(pgdp);
+ pgd = READ_ONCE(*pgdp);
+ WARN_ON(!pgd_none(pgd));
+}
+
+static void __init pgd_populate_tests(struct mm_struct *mm, pgd_t *pgdp,
+ p4d_t *p4dp)
+{
+ pgd_t pgd;
+
+ if (mm_p4d_folded(mm))
+ return;
+
+ /*
+ * This entry points to next level page table page.
+ * Hence this must not qualify as pgd_bad().
+ */
+ p4d_clear(p4dp);
+ pgd_clear(pgdp);
+ pgd_populate(mm, pgdp, p4dp);
+ pgd = READ_ONCE(*pgdp);
+ WARN_ON(pgd_bad(pgd));
+}
+#else
+static void __init p4d_clear_tests(struct mm_struct *mm, p4d_t *p4dp) { }
+static void __init pgd_clear_tests(struct mm_struct *mm, pgd_t *pgdp) { }
+static void __init p4d_populate_tests(struct mm_struct *mm, p4d_t *p4dp,
+ pud_t *pudp)
+{
+}
+static void __init pgd_populate_tests(struct mm_struct *mm, pgd_t *pgdp,
+ p4d_t *p4dp)
+{
+}
+#endif
+
+static void __init pte_clear_tests(struct mm_struct *mm, pte_t *ptep)
+{
+ pte_t pte = READ_ONCE(*ptep);
+
+ pte = __pte(pte_val(pte) | RANDOM_ORVALUE);
+ WRITE_ONCE(*ptep, pte);
+ pte_clear(mm, 0, ptep);
+ pte = READ_ONCE(*ptep);
+ WARN_ON(!pte_none(pte));
+}
+
+static void __init pmd_clear_tests(struct mm_struct *mm, pmd_t *pmdp)
+{
+ pmd_t pmd = READ_ONCE(*pmdp);
+
+ pmd = __pmd(pmd_val(pmd) | RANDOM_ORVALUE);
+ WRITE_ONCE(*pmdp, pmd);
+ pmd_clear(pmdp);
+ pmd = READ_ONCE(*pmdp);
+ WARN_ON(!pmd_none(pmd));
+}
+
+static void __init pmd_populate_tests(struct mm_struct *mm, pmd_t *pmdp,
+ pgtable_t pgtable)
+{
+ pmd_t pmd;
+
+ /*
+ * This entry points to next level page table page.
+ * Hence this must not qualify as pmd_bad().
+ */
+ pmd_clear(pmdp);
+ pmd_populate(mm, pmdp, pgtable);
+ pmd = READ_ONCE(*pmdp);
+ WARN_ON(pmd_bad(pmd));
+}
+
+static unsigned long __init get_random_vaddr(void)
+{
+ unsigned long random_vaddr, random_pages, total_user_pages;
+
+ total_user_pages = (TASK_SIZE - FIRST_USER_ADDRESS) / PAGE_SIZE;
+
+ random_pages = get_random_long() % total_user_pages;
+ random_vaddr = FIRST_USER_ADDRESS + random_pages * PAGE_SIZE;
+
+ return random_vaddr;
+}
+
+void __init debug_vm_pgtable(void)
+{
+ struct mm_struct *mm;
+ pgd_t *pgdp;
+ p4d_t *p4dp, *saved_p4dp;
+ pud_t *pudp, *saved_pudp;
+ pmd_t *pmdp, *saved_pmdp, pmd;
+ pte_t *ptep;
+ pgtable_t saved_ptep;
+ pgprot_t prot;
+ phys_addr_t paddr;
+ unsigned long vaddr, pte_aligned, pmd_aligned;
+ unsigned long pud_aligned, p4d_aligned, pgd_aligned;
+
+ pr_info("Validating architecture page table helpers\n");
+ prot = vm_get_page_prot(VMFLAGS);
+ vaddr = get_random_vaddr();
+ mm = mm_alloc();
+ if (!mm) {
+ pr_err("mm_struct allocation failed\n");
+ return;
+ }
+
+ /*
+ * PFN for mapping at PTE level is determined from a standard kernel
+ * text symbol. But pfns for higher page table levels are derived by
+ * masking lower bits of this real pfn. These derived pfns might not
+ * exist on the platform but that does not really matter as pfn_pxx()
+ * helpers will still create appropriate entries for the test. This
+ * helps avoid large memory block allocations to be used for mapping
+ * at higher page table levels.
+ */
+ paddr = __pa(&start_kernel);
+
+ pte_aligned = (paddr & PAGE_MASK) >> PAGE_SHIFT;
+ pmd_aligned = (paddr & PMD_MASK) >> PAGE_SHIFT;
+ pud_aligned = (paddr & PUD_MASK) >> PAGE_SHIFT;
+ p4d_aligned = (paddr & P4D_MASK) >> PAGE_SHIFT;
+ pgd_aligned = (paddr & PGDIR_MASK) >> PAGE_SHIFT;
+ WARN_ON(!pfn_valid(pte_aligned));
+
+ pgdp = pgd_offset(mm, vaddr);
+ p4dp = p4d_alloc(mm, pgdp, vaddr);
+ pudp = pud_alloc(mm, p4dp, vaddr);
+ pmdp = pmd_alloc(mm, pudp, vaddr);
+ ptep = pte_alloc_map(mm, pmdp, vaddr);
+
+ /*
+ * Save all the page table page addresses as the page table
+ * entries will be used for testing with random or garbage
+ * values. These saved addresses will be used for freeing
+ * page table pages.
+ */
+ pmd = READ_ONCE(*pmdp);
+ saved_p4dp = p4d_offset(pgdp, 0UL);
+ saved_pudp = pud_offset(p4dp, 0UL);
+ saved_pmdp = pmd_offset(pudp, 0UL);
+ saved_ptep = pmd_pgtable(pmd);
+
+ pte_basic_tests(pte_aligned, prot);
+ pmd_basic_tests(pmd_aligned, prot);
+ pud_basic_tests(pud_aligned, prot);
+ p4d_basic_tests(p4d_aligned, prot);
+ pgd_basic_tests(pgd_aligned, prot);
+
+ pte_clear_tests(mm, ptep);
+ pmd_clear_tests(mm, pmdp);
+ pud_clear_tests(mm, pudp);
+ p4d_clear_tests(mm, p4dp);
+ pgd_clear_tests(mm, pgdp);
+
+ pte_unmap(ptep);
+
+ pmd_populate_tests(mm, pmdp, saved_ptep);
+ pud_populate_tests(mm, pudp, saved_pmdp);
+ p4d_populate_tests(mm, p4dp, saved_pudp);
+ pgd_populate_tests(mm, pgdp, saved_p4dp);
+
+ p4d_free(mm, saved_p4dp);
+ pud_free(mm, saved_pudp);
+ pmd_free(mm, saved_pmdp);
+ pte_free(mm, saved_ptep);
+
+ mm_dec_nr_puds(mm);
+ mm_dec_nr_pmds(mm);
+ mm_dec_nr_ptes(mm);
+ mmdrop(mm);
+}
--
2.20.1
^ permalink raw reply related
* Re: [PATCH v6 09/10] mm/memory_hotplug: Drop local variables in shrink_zone_span()
From: Wei Yang @ 2020-02-05 10:07 UTC (permalink / raw)
To: David Hildenbrand
Cc: linux-s390, Michal Hocko, linux-ia64, Pavel Tatashin, linux-sh,
x86, linux-kernel, linux-mm, Wei Yang, Andrew Morton,
linuxppc-dev, Dan Williams, linux-arm-kernel, Oscar Salvador
In-Reply-To: <20191006085646.5768-10-david@redhat.com>
On Sun, Oct 06, 2019 at 10:56:45AM +0200, David Hildenbrand wrote:
>Get rid of the unnecessary local variables.
>
>Cc: Andrew Morton <akpm@linux-foundation.org>
>Cc: Oscar Salvador <osalvador@suse.de>
>Cc: David Hildenbrand <david@redhat.com>
>Cc: Michal Hocko <mhocko@suse.com>
>Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
>Cc: Dan Williams <dan.j.williams@intel.com>
>Cc: Wei Yang <richardw.yang@linux.intel.com>
>Signed-off-by: David Hildenbrand <david@redhat.com>
Looks reasonable.
Reviewed-by: Wei Yang <richardw.yang@linux.intel.com>
>---
> mm/memory_hotplug.c | 15 ++++++---------
> 1 file changed, 6 insertions(+), 9 deletions(-)
>
>diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
>index 8dafa1ba8d9f..843481bd507d 100644
>--- a/mm/memory_hotplug.c
>+++ b/mm/memory_hotplug.c
>@@ -374,14 +374,11 @@ static unsigned long find_biggest_section_pfn(int nid, struct zone *zone,
> static void shrink_zone_span(struct zone *zone, unsigned long start_pfn,
> unsigned long end_pfn)
> {
>- unsigned long zone_start_pfn = zone->zone_start_pfn;
>- unsigned long z = zone_end_pfn(zone); /* zone_end_pfn namespace clash */
>- unsigned long zone_end_pfn = z;
> unsigned long pfn;
> int nid = zone_to_nid(zone);
>
> zone_span_writelock(zone);
>- if (zone_start_pfn == start_pfn) {
>+ if (zone->zone_start_pfn == start_pfn) {
> /*
> * If the section is smallest section in the zone, it need
> * shrink zone->zone_start_pfn and zone->zone_spanned_pages.
>@@ -389,25 +386,25 @@ static void shrink_zone_span(struct zone *zone, unsigned long start_pfn,
> * for shrinking zone.
> */
> pfn = find_smallest_section_pfn(nid, zone, end_pfn,
>- zone_end_pfn);
>+ zone_end_pfn(zone));
> if (pfn) {
>+ zone->spanned_pages = zone_end_pfn(zone) - pfn;
> zone->zone_start_pfn = pfn;
>- zone->spanned_pages = zone_end_pfn - pfn;
> } else {
> zone->zone_start_pfn = 0;
> zone->spanned_pages = 0;
> }
>- } else if (zone_end_pfn == end_pfn) {
>+ } else if (zone_end_pfn(zone) == end_pfn) {
> /*
> * If the section is biggest section in the zone, it need
> * shrink zone->spanned_pages.
> * In this case, we find second biggest valid mem_section for
> * shrinking zone.
> */
>- pfn = find_biggest_section_pfn(nid, zone, zone_start_pfn,
>+ pfn = find_biggest_section_pfn(nid, zone, zone->zone_start_pfn,
> start_pfn);
> if (pfn)
>- zone->spanned_pages = pfn - zone_start_pfn + 1;
>+ zone->spanned_pages = pfn - zone->zone_start_pfn + 1;
> else {
> zone->zone_start_pfn = 0;
> zone->spanned_pages = 0;
>--
>2.21.0
--
Wei Yang
Help you, Help me
^ permalink raw reply
* Re: [PATCH v6 08/10] mm/memory_hotplug: Don't check for "all holes" in shrink_zone_span()
From: Wei Yang @ 2020-02-05 9:59 UTC (permalink / raw)
To: David Hildenbrand
Cc: linux-s390, Michal Hocko, linux-ia64, Pavel Tatashin, linux-sh,
x86, linux-kernel, linux-mm, Wei Yang, Andrew Morton,
linuxppc-dev, Dan Williams, linux-arm-kernel, Oscar Salvador
In-Reply-To: <20191006085646.5768-9-david@redhat.com>
On Sun, Oct 06, 2019 at 10:56:44AM +0200, David Hildenbrand wrote:
>If we have holes, the holes will automatically get detected and removed
>once we remove the next bigger/smaller section. The extra checks can
>go.
>
>Cc: Andrew Morton <akpm@linux-foundation.org>
>Cc: Oscar Salvador <osalvador@suse.de>
>Cc: Michal Hocko <mhocko@suse.com>
>Cc: David Hildenbrand <david@redhat.com>
>Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
>Cc: Dan Williams <dan.j.williams@intel.com>
>Cc: Wei Yang <richardw.yang@linux.intel.com>
>Signed-off-by: David Hildenbrand <david@redhat.com>
>---
> mm/memory_hotplug.c | 34 +++++++---------------------------
> 1 file changed, 7 insertions(+), 27 deletions(-)
>
>diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
>index f294918f7211..8dafa1ba8d9f 100644
>--- a/mm/memory_hotplug.c
>+++ b/mm/memory_hotplug.c
>@@ -393,6 +393,9 @@ static void shrink_zone_span(struct zone *zone, unsigned long start_pfn,
> if (pfn) {
> zone->zone_start_pfn = pfn;
> zone->spanned_pages = zone_end_pfn - pfn;
>+ } else {
>+ zone->zone_start_pfn = 0;
>+ zone->spanned_pages = 0;
> }
> } else if (zone_end_pfn == end_pfn) {
> /*
>@@ -405,34 +408,11 @@ static void shrink_zone_span(struct zone *zone, unsigned long start_pfn,
> start_pfn);
> if (pfn)
> zone->spanned_pages = pfn - zone_start_pfn + 1;
>+ else {
>+ zone->zone_start_pfn = 0;
>+ zone->spanned_pages = 0;
>+ }
> }
If it is me, I would like to take out these two similar logic out.
For example:
if () {
} else if () {
} else {
goto out;
}
/* The zone has no valid section */
if (!pfn) {
zone->zone_start_pfn = 0;
zone->spanned_pages = 0;
}
out:
zone_span_writeunlock(zone);
Well, this is just my personal taste :-)
>-
>- /*
>- * The section is not biggest or smallest mem_section in the zone, it
>- * only creates a hole in the zone. So in this case, we need not
>- * change the zone. But perhaps, the zone has only hole data. Thus
>- * it check the zone has only hole or not.
>- */
>- pfn = zone_start_pfn;
>- for (; pfn < zone_end_pfn; pfn += PAGES_PER_SUBSECTION) {
>- if (unlikely(!pfn_to_online_page(pfn)))
>- continue;
>-
>- if (page_zone(pfn_to_page(pfn)) != zone)
>- continue;
>-
>- /* Skip range to be removed */
>- if (pfn >= start_pfn && pfn < end_pfn)
>- continue;
>-
>- /* If we find valid section, we have nothing to do */
>- zone_span_writeunlock(zone);
>- return;
>- }
>-
>- /* The zone has no valid section */
>- zone->zone_start_pfn = 0;
>- zone->spanned_pages = 0;
> zone_span_writeunlock(zone);
> }
>
>--
>2.21.0
--
Wei Yang
Help you, Help me
^ permalink raw reply
* Re: [PATCH v6 07/10] mm/memory_hotplug: We always have a zone in find_(smallest|biggest)_section_pfn
From: Wei Yang @ 2020-02-05 9:26 UTC (permalink / raw)
To: David Hildenbrand
Cc: linux-s390, Michal Hocko, linux-ia64, Pavel Tatashin, linux-sh,
x86, linux-kernel, linux-mm, Wei Yang, Andrew Morton,
linuxppc-dev, Dan Williams, linux-arm-kernel, Oscar Salvador
In-Reply-To: <80d3baea-2076-ed07-1216-27d8aa8c8734@redhat.com>
On Wed, Feb 05, 2020 at 09:59:41AM +0100, David Hildenbrand wrote:
>On 05.02.20 09:57, Wei Yang wrote:
>> On Sun, Oct 06, 2019 at 10:56:43AM +0200, David Hildenbrand wrote:
>>> With shrink_pgdat_span() out of the way, we now always have a valid
>>> zone.
>>>
>>> Cc: Andrew Morton <akpm@linux-foundation.org>
>>> Cc: Oscar Salvador <osalvador@suse.de>
>>> Cc: David Hildenbrand <david@redhat.com>
>>> Cc: Michal Hocko <mhocko@suse.com>
>>> Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
>>> Cc: Dan Williams <dan.j.williams@intel.com>
>>> Cc: Wei Yang <richardw.yang@linux.intel.com>
>>> Signed-off-by: David Hildenbrand <david@redhat.com>
>>
>> Reviewed-by: Wei Yang <richardw.yang@linux.intel.com>
>
>Just FYI, the patches are now upstream, so the rb's can no longer be
>applied. (but we can send fixes if we find that something is broken ;)
>). Thanks!
>
Thanks for reminding. :-)
>--
>Thanks,
>
>David / dhildenb
--
Wei Yang
Help you, Help me
^ permalink raw reply
* Re: [PATCH v6 07/10] mm/memory_hotplug: We always have a zone in find_(smallest|biggest)_section_pfn
From: David Hildenbrand @ 2020-02-05 8:59 UTC (permalink / raw)
To: Wei Yang
Cc: linux-s390, Michal Hocko, linux-ia64, Pavel Tatashin, linux-sh,
x86, linux-kernel, linux-mm, Andrew Morton, linuxppc-dev,
Dan Williams, linux-arm-kernel, Oscar Salvador
In-Reply-To: <20200205085709.GA24162@richard>
On 05.02.20 09:57, Wei Yang wrote:
> On Sun, Oct 06, 2019 at 10:56:43AM +0200, David Hildenbrand wrote:
>> With shrink_pgdat_span() out of the way, we now always have a valid
>> zone.
>>
>> Cc: Andrew Morton <akpm@linux-foundation.org>
>> Cc: Oscar Salvador <osalvador@suse.de>
>> Cc: David Hildenbrand <david@redhat.com>
>> Cc: Michal Hocko <mhocko@suse.com>
>> Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
>> Cc: Dan Williams <dan.j.williams@intel.com>
>> Cc: Wei Yang <richardw.yang@linux.intel.com>
>> Signed-off-by: David Hildenbrand <david@redhat.com>
>
> Reviewed-by: Wei Yang <richardw.yang@linux.intel.com>
Just FYI, the patches are now upstream, so the rb's can no longer be
applied. (but we can send fixes if we find that something is broken ;)
). Thanks!
--
Thanks,
David / dhildenb
^ permalink raw reply
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