On 9/24/19 7:39 AM, Vlastimil Babka wrote:
> On 9/20/19 1:37 AM, Nitin Gupta wrote:
>> On Tue, 2019-08-20 at 10:46 +0200, Vlastimil Babka wrote:
>>>
>>> That's a lot of control knobs - how is an admin supposed to tune them to
>>> their
>>> needs?
>>
>>
>> Yes, it's difficult for an admin to get so
On 9/20/19 1:37 AM, Nitin Gupta wrote:
> On Tue, 2019-08-20 at 10:46 +0200, Vlastimil Babka wrote:
>>
>> That's a lot of control knobs - how is an admin supposed to tune them to
>> their
>> needs?
>
>
> Yes, it's difficult for an admin to get so many tunable right unless
> targeting a very specif
On Tue, 2019-08-20 at 10:46 +0200, Vlastimil Babka wrote:
> > This patch is largely based on ideas from Michal Hocko posted here:
> > https://lore.kernel.org/linux-mm/20161230131412.gi13...@dhcp22.suse.cz/
> >
> > Testing done (on x86):
> > - Set /sys/kernel/mm/compaction/order-9/extfrag_{low,hi
On Thu, 2019-08-22 at 09:51 +0100, Mel Gorman wrote:
> As unappealing as it sounds, I think it is better to try improve the
> allocation latency itself instead of trying to hide the cost in a kernel
> thread. It's far harder to implement as compaction is not easy but it
> would be more obvious what
On Tue, 17 Sep 2019, John Hubbard wrote:
> > We've had good success with periodically compacting memory on a regular
> > cadence on systems with hugepages enabled. The cadence itself is defined
> > by the admin but it causes khugepaged[*] to periodically wakeup and invoke
> > compaction in an
On 9/16/19 1:16 PM, David Rientjes wrote:
> On Fri, 16 Aug 2019, Nitin Gupta wrote:
...
>
> We've had good success with periodically compacting memory on a regular
> cadence on systems with hugepages enabled. The cadence itself is defined
> by the admin but it causes khugepaged[*] to periodical
On Mon, 2019-09-16 at 13:16 -0700, David Rientjes wrote:
> On Fri, 16 Aug 2019, Nitin Gupta wrote:
>
> > For some applications we need to allocate almost all memory as
> > hugepages. However, on a running system, higher order allocations can
> > fail if the memory is fragmented. Linux kernel curre
On Fri, 16 Aug 2019, Nitin Gupta wrote:
> For some applications we need to allocate almost all memory as
> hugepages. However, on a running system, higher order allocations can
> fail if the memory is fragmented. Linux kernel currently does
> on-demand compaction as we request more hugepages but t
On Mon, 2019-08-26 at 12:47 +0100, Mel Gorman wrote:
> On Thu, Aug 22, 2019 at 09:57:22PM +, Nitin Gupta wrote:
> > > Note that proactive compaction may reduce allocation latency but
> > > it is not
> > > free either. Even though the scanning and migration may happen in
> > > a kernel
> > > thr
On Thu, Aug 22, 2019 at 09:57:22PM +, Nitin Gupta wrote:
> > Note that proactive compaction may reduce allocation latency but it is not
> > free either. Even though the scanning and migration may happen in a kernel
> > thread, tasks can incur faults while waiting for compaction to complete if
On 8/20/19 2:46 AM, Vlastimil Babka wrote:
> +CC Khalid Aziz who proposed a different approach:
> https://lore.kernel.org/linux-mm/20190813014012.30232-1-khalid.a...@oracle.com/T/#u
>
> On 8/16/19 11:43 PM, Nitin Gupta wrote:
>> The patch has plenty of rough edges but posting it early to see if I'
> ; Qian Cai ; Andrey Ryabinin
> ; Roman Gushchin ; Greg Kroah-
> Hartman ; Kees Cook
> ; Jann Horn ; Johannes
> Weiner ; Arun KS ; Janne
> Huttunen ; Konstantin Khlebnikov
> ; linux-kernel@vger.kernel.org; linux-
> m...@kvack.org
> Subject: Re: [RFC] mm: Proactive compaction
>
On Fri, Aug 16, 2019 at 02:43:30PM -0700, Nitin Gupta wrote:
> For some applications we need to allocate almost all memory as
> hugepages. However, on a running system, higher order allocations can
> fail if the memory is fragmented. Linux kernel currently does
> on-demand compaction as we request
ntel.com; Yu Zhao ; Qian Cai
> ; Andrey Ryabinin ; Roman
> Gushchin ; Greg Kroah-Hartman
> ; Kees Cook ; Jann
> Horn ; Johannes Weiner ; Arun
> KS ; Janne Huttunen
> ; Konstantin Khlebnikov
> ; linux-kernel@vger.kernel.org; linux-
> m...@kvack.org
> Subject: Re: [RFC] mm: P
On Fri, Aug 16, 2019 at 02:43:30PM -0700, Nitin Gupta wrote:
> Testing done (on x86):
> - Set /sys/kernel/mm/compaction/order-9/extfrag_{low,high} = {25, 30}
> respectively.
> - Use a test program to fragment memory: the program allocates all memory
> and then for each 2M aligned section, frees
binin ; Roman
> Gushchin ; Greg Kroah-Hartman
> ; Kees Cook ; Jann
> Horn ; Johannes Weiner ; Arun
> KS ; Janne Huttunen
> ; Konstantin Khlebnikov
> ; linux-kernel@vger.kernel.org; linux-
> m...@kvack.org; Khalid Aziz
> Subject: Re: [RFC] mm: Proactive compaction
>
+CC Khalid Aziz who proposed a different approach:
https://lore.kernel.org/linux-mm/20190813014012.30232-1-khalid.a...@oracle.com/T/#u
On 8/16/19 11:43 PM, Nitin Gupta wrote:
> For some applications we need to allocate almost all memory as
> hugepages. However, on a running system, higher order al
For some applications we need to allocate almost all memory as
hugepages. However, on a running system, higher order allocations can
fail if the memory is fragmented. Linux kernel currently does
on-demand compaction as we request more hugepages but this style of
compaction incurs very high latency.
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