Hi Cristian, Responses inline below.
Regards Alan > -----Original Message----- > From: Dumitrescu, Cristian [mailto:cristian.dumitre...@intel.com] > Sent: Thursday, January 11, 2018 1:11 PM > To: alangordonde...@gmail.com > Cc: dev@dpdk.org; Alan Dewar <alan.de...@att.com>; Kantecki, Tomasz > <tomasz.kante...@intel.com>; Singh, Jasvinder <jasvinder.si...@intel.com> > Subject: RE: [PATCH v5] sched: make RED scaling configurable > > Hi Alan, > > More issues and questions below: > >...<snip> > > > diff --git a/lib/librte_sched/rte_red.c b/lib/librte_sched/rte_red.h > I suggest we use uint32_t for rte_red_scaling and rte_red_max_threshold, even > though their values can fit into uint8_t and uint16_t respectively. Will do. > > diff --git a/lib/librte_sched/rte_red.c b/lib/librte_sched/rte_red.c > > +int > > +rte_red_set_scaling(uint16_t max_red_queue_length) { > > + int8_t count; > > + > > + if (rte_red_init_done) > > + /** > > + * Can't change the scaling once the red table has been > > + * computed. > > + */ > > + return -1; > > Is there a reason why we cannot simply reset the scaling here? Actually we could, but I was originally thinking that you might be happier keeping with a one-time RED initialization function, but then had to introduce the rte_reset_red_scaling function for the unit-tests. I'm happy to do RED reinitialization here, if you are. > > + > > + if (max_red_queue_length < RTE_RED_MIN_QUEUE_LENGTH) > > + return -2; > > + > > + if (max_red_queue_length > RTE_RED_MAX_QUEUE_LENGTH) > > + return -3; > > + > > + if (!rte_is_power_of_2(max_red_queue_length)) > > + return -4; > > + > > + count = 0; > > + while (max_red_queue_length != 0) { > > + max_red_queue_length >>= 1; > > + count++; > > + } > > This does not look right to me. I think you want to compute the log2 of > max_red_queue_length here, but your result (count) is bigger by 1 than it > should be, right? > When max_red_queue_length = RTE_RED_DEFAULT_QUEUE_LENGTH = 1024, the result > should be: count = RTE_RED_SCALING = 10, not 11. > Well spotted. > I suggest you use rte_bsf32() function for this purpose. I wasn't aware of this function, it appears to do the necessary so will do. > > + > > + rte_red_scaling -= count - RTE_RED_SCALING; > > Why not simply: rte_red_scaling = count? Stupidity on my part! - Will do. > > + rte_red_max_threshold = max_red_queue_length - 1; > > + return 0; > > +} > > + > > > diff --git a/lib/librte_sched/rte_sched_version.map > > b/lib/librte_sched/rte_sched_version.map > > index 3aa159a..262bece 100644 > > --- a/lib/librte_sched/rte_sched_version.map > > +++ b/lib/librte_sched/rte_sched_version.map > > @@ -29,3 +29,10 @@ DPDK_2.1 { > > rte_sched_port_pkt_read_color; > > > > } DPDK_2.0; > > + > > +DPDK_17.08 { > > + global; > > + > > + __rte_red_reset; > > + rte_red_set_scaling; > > +} DPDK_2.1; > > You need to put the correct DPDK release number here. Will do. > You also need to do more work to make sure the share library support is not > broken: > -need to increase LIBABIVER in Makefile > -need to update the library .so number in release notes -need to check that > build does not fail for shared libraries > > (You can use this patch as example: > https://urldefense.proofpoint.com/v2/url?u=https-3A__dpdk.org_dev_patchwork_patch_33109_&d=DwIFAg&c=LFYZ-o9_HUMeMTSQicvjIg&r=MSobi4bsl2plY_3b1jvY6kXt-SHzSxMj5YhuyxfTjJE&m=D7OTgDyX27pcg-xs8N7FQzX4lAkkcPqbPAhJp_IyrNI&s=mCvsqitq8Y6vD3UC-r1WEGtrRp17bsmJaEHGby97zYw&e= > ) Okay, I need to look into this stuff - I'll come back with some questions if anything isn't clear. > > diff --git a/test/test/test_red.c b/test/test/test_red.c > The RED test code fails to link, please fix: Yes - will do. > export RTE_TARGET=x86_64-native-linuxapp-gcc > > [ ]$ ~/git_dpdk_red/dpdk$ make -C test/test > make: Entering directory 'dpdk/test/test' >...<snip> > LD test > test_red.o: In function `test_rte_red_init': > test_red.c:(.text+0x2cd): undefined reference to `__rte_red_reset' > test_red.c:(.text+0x2da): undefined reference to `rte_red_set_scaling' > test_red.c:(.text+0x2ed): undefined reference to `rte_red_max_threshold' > test_red.o: In function `increase_actual_qsize': > test_red.c:(.text+0x48c): undefined reference to `rte_red_scaling' > test_red.c:(.text+0x533): undefined reference to `rte_red_scaling' > test_red.o: In function `enqueue_dequeue_func': > test_red.c:(.text+0x70c): undefined reference to `rte_red_scaling' > test_red.c:(.text+0x7a5): undefined reference to `rte_red_scaling' > test_red.o: In function `increase_average_qsize': > test_red.c:(.text+0x95c): undefined reference to `rte_red_scaling' > test_red.o:test_red.c:(.text+0x9f1): more undefined references to > `rte_red_scaling' follow > collect2: error: ld returned 1 exit status > dpdk/mk/rte.app.mk:306: recipe for target 'test' failed > make: *** [test] Error 1 > make: Leaving directory 'dpdk/test/test' > > Regards, > Cristian
