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Diffstat (limited to 'Documentation/networking/gen_stats.txt')
| -rw-r--r-- | Documentation/networking/gen_stats.txt | 119 |
1 files changed, 0 insertions, 119 deletions
diff --git a/Documentation/networking/gen_stats.txt b/Documentation/networking/gen_stats.txt deleted file mode 100644 index 179b18ce45ff..000000000000 --- a/Documentation/networking/gen_stats.txt +++ /dev/null @@ -1,119 +0,0 @@ -Generic networking statistics for netlink users -====================================================================== - -Statistic counters are grouped into structs: - -Struct TLV type Description ----------------------------------------------------------------------- -gnet_stats_basic TCA_STATS_BASIC Basic statistics -gnet_stats_rate_est TCA_STATS_RATE_EST Rate estimator -gnet_stats_queue TCA_STATS_QUEUE Queue statistics -none TCA_STATS_APP Application specific - - -Collecting: ------------ - -Declare the statistic structs you need: -struct mystruct { - struct gnet_stats_basic bstats; - struct gnet_stats_queue qstats; - ... -}; - -Update statistics, in dequeue() methods only, (while owning qdisc->running) -mystruct->tstats.packet++; -mystruct->qstats.backlog += skb->pkt_len; - - -Export to userspace (Dump): ---------------------------- - -my_dumping_routine(struct sk_buff *skb, ...) -{ - struct gnet_dump dump; - - if (gnet_stats_start_copy(skb, TCA_STATS2, &mystruct->lock, &dump, - TCA_PAD) < 0) - goto rtattr_failure; - - if (gnet_stats_copy_basic(&dump, &mystruct->bstats) < 0 || - gnet_stats_copy_queue(&dump, &mystruct->qstats) < 0 || - gnet_stats_copy_app(&dump, &xstats, sizeof(xstats)) < 0) - goto rtattr_failure; - - if (gnet_stats_finish_copy(&dump) < 0) - goto rtattr_failure; - ... -} - -TCA_STATS/TCA_XSTATS backward compatibility: --------------------------------------------- - -Prior users of struct tc_stats and xstats can maintain backward -compatibility by calling the compat wrappers to keep providing the -existing TLV types. - -my_dumping_routine(struct sk_buff *skb, ...) -{ - if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, - TCA_XSTATS, &mystruct->lock, &dump, - TCA_PAD) < 0) - goto rtattr_failure; - ... -} - -A struct tc_stats will be filled out during gnet_stats_copy_* calls -and appended to the skb. TCA_XSTATS is provided if gnet_stats_copy_app -was called. - - -Locking: --------- - -Locks are taken before writing and released once all statistics have -been written. Locks are always released in case of an error. You -are responsible for making sure that the lock is initialized. - - -Rate Estimator: --------------- - -0) Prepare an estimator attribute. Most likely this would be in user - space. The value of this TLV should contain a tc_estimator structure. - As usual, such a TLV needs to be 32 bit aligned and therefore the - length needs to be appropriately set, etc. The estimator interval - and ewma log need to be converted to the appropriate values. - tc_estimator.c::tc_setup_estimator() is advisable to be used as the - conversion routine. It does a few clever things. It takes a time - interval in microsecs, a time constant also in microsecs and a struct - tc_estimator to be populated. The returned tc_estimator can be - transported to the kernel. Transfer such a structure in a TLV of type - TCA_RATE to your code in the kernel. - -In the kernel when setting up: -1) make sure you have basic stats and rate stats setup first. -2) make sure you have initialized stats lock that is used to setup such - stats. -3) Now initialize a new estimator: - - int ret = gen_new_estimator(my_basicstats,my_rate_est_stats, - mystats_lock, attr_with_tcestimator_struct); - - if ret == 0 - success - else - failed - -From now on, every time you dump my_rate_est_stats it will contain -up-to-date info. - -Once you are done, call gen_kill_estimator(my_basicstats, -my_rate_est_stats) Make sure that my_basicstats and my_rate_est_stats -are still valid (i.e still exist) at the time of making this call. - - -Authors: --------- -Thomas Graf <tgraf@suug.ch> -Jamal Hadi Salim <hadi@cyberus.ca> |