From: David Hunt Date: Wed, 9 Mar 2022 13:22:21 +0000 (+0000) Subject: doc: add PMD power management errata with RTM and GCC 9 X-Git-Url: http://git.droids-corp.org/?a=commitdiff_plain;h=ba7b205a9865a85ceb71b6135a3097826af3286d;p=dpdk.git doc: add PMD power management errata with RTM and GCC 9 An errata exists where users may see reduced power savings when using PMD Power Management. This issue occurs when compiling DPDK applications with GCC-9 on platforms with TSX enabled. In rte_power_monitor_multi(), the function may return without successfully starting the RTM transaction (the _xbegin() fails). Signed-off-by: David Hunt --- diff --git a/doc/guides/rel_notes/release_22_03.rst b/doc/guides/rel_notes/release_22_03.rst index d231e3e8a4..5ad9ea3728 100644 --- a/doc/guides/rel_notes/release_22_03.rst +++ b/doc/guides/rel_notes/release_22_03.rst @@ -313,6 +313,18 @@ Known Issues Also, make sure to start the actual text at the margin. ======================================================= +* **Possible reduced power saving with PMD Power Management.** + + Users may see reduced power savings when using PMD Power Management. + This issue occurs when compiling DPDK applications with GCC-9 + on platforms with TSX enabled. + The function ``rte_power_monitor_multi()`` may return + without successfully starting the RTM transaction (``_xbegin()`` fails). + + There are three workarounds for this issue. + Either build DPDK with GCC-11 or newer, build with shared libraries, + or build DPDK with fewer drivers. + Tested Platforms ----------------