[dpdk-dev,v2] doc: add use of mlockall to programmers guide
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Commit Message
When I was adding mlockall() to the testpmd application it was
suggested to add a reference to the use case of mlockall(). This patch
adds is.
Signed-off-by: Eelco Chaudron <echaudro@redhat.com>
---
doc/guides/prog_guide/writing_efficient_code.rst | 15 +++++++++++++++
1 file changed, 15 insertions(+)
Comments
> -----Original Message-----
> From: Eelco Chaudron [mailto:echaudro@redhat.com]
> Sent: Monday, October 2, 2017 11:02 AM
> To: Mcnamara, John <john.mcnamara@intel.com>
> Cc: dev@dpdk.org
> Subject: [PATCH v2] doc: add use of mlockall to programmers guide
>
> When I was adding mlockall() to the testpmd application it was suggested
> to add a reference to the use case of mlockall(). This patch adds is.
>
> Signed-off-by: Eelco Chaudron <echaudro@redhat.com>
Acked-by: John McNamara <john.mcnamara@intel.com>
On 10/2/2017 11:11 AM, Mcnamara, John wrote:
>
>
>> -----Original Message-----
>> From: Eelco Chaudron [mailto:echaudro@redhat.com]
>> Sent: Monday, October 2, 2017 11:02 AM
>> To: Mcnamara, John <john.mcnamara@intel.com>
>> Cc: dev@dpdk.org
>> Subject: [PATCH v2] doc: add use of mlockall to programmers guide
>>
>> When I was adding mlockall() to the testpmd application it was suggested
>> to add a reference to the use case of mlockall(). This patch adds is.
>>
>> Signed-off-by: Eelco Chaudron <echaudro@redhat.com>
>
> Acked-by: John McNamara <john.mcnamara@intel.com>
Applied to dpdk/master, thanks.
@@ -105,6 +105,21 @@ meaning that if all memory access operations are done on the first channel only,
By default, the :ref:`Mempool Library <Mempool_Library>` spreads the addresses of objects among memory channels.
+Locking memory pages
+~~~~~~~~~~~~~~~~~~~~
+
+The underlying operating system is allowed to load/unload memory pages at its own discretion.
+These page loads could impact the performance, as the process is on hold when the kernel fetches them.
+
+To avoid these you could pre-load, and lock them into memory with the ``mlockall()`` call.
+
+.. code-block:: c
+
+ if (mlockall(MCL_CURRENT | MCL_FUTURE)) {
+ RTE_LOG(NOTICE, USER1, "mlockall() failed with error \"%s\"\n",
+ strerror(errno));
+ }
+
Communication Between lcores
----------------------------