On 6/20/19 10:07 PM, Eads, Gage wrote:
-----Original Message-----
From: Andrew Rybchenko [mailto:[email protected]]
Sent: Thursday, June 20, 2019 1:01 PM
To: Eads, Gage <[email protected]>; [email protected]
Cc: [email protected]; [email protected]
Subject: Re: [PATCH] doc: add multi-proc shared lib mempool note
On 6/18/19 9:48 PM, Gage Eads wrote:
The mempool library assigns handler ops indexes based on the dynamic
load order of mempool handlers. Indexes are used so a mempool can be
used by multiple processes, but this only works if all processes agree
on the mapping from index to mempool handler.
When using the '-d' argument, it's possible for different processes to
load mempool handlers in different orders, and thus have different
index->handler mappings. Using a mempool in multiple of such processes
index->will
result in undefined behavior.
This commit adds a note to the mempool library programmer's guide
warning users against this.
Fixes: 449c49b93a6b ("mempool: support handler operations")
Cc: [email protected]
Signed-off-by: Gage Eads <[email protected]>
---
doc/guides/prog_guide/mempool_lib.rst | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/doc/guides/prog_guide/mempool_lib.rst
b/doc/guides/prog_guide/mempool_lib.rst
index 52a569f57..4470f6b38 100644
--- a/doc/guides/prog_guide/mempool_lib.rst
+++ b/doc/guides/prog_guide/mempool_lib.rst
@@ -133,6 +133,13 @@ For applications that use ``rte_pktmbuf_create()``,
there is a config setting
(``RTE_MBUF_DEFAULT_MEMPOOL_OPS``) that allows the application to
make use of
an alternative mempool handler.
+ .. note::
+
+ When running a DPDK application with shared libraries, mempool
handler
+ shared objects specified with the '-d' EAL command-line parameter are
+ dynamically loaded. When running a multi-process application with
shared
+ libraries, the -d arguments for mempool handlers *must be specified in
the
+ same order for all processes* to ensure correct operation.
One more empty line is required here, other than that:
Acked-by: Andrew Rybchenko <[email protected]>
Can do. Just for my understanding, why is the extra empty line required?
https://doc.dpdk.org/guides/contributing/documentation.html#whitespace
* Add 2 blank lines before each section header.
