From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jamal Hadi Salim Subject: Re: [PATCH net-next v4 2/2] net sched actions: add time filter for action dumping Date: Wed, 19 Apr 2017 09:11:26 -0400 Message-ID: References: <1492603050-9318-1-git-send-email-jhs@emojatatu.com> <1492603050-9318-2-git-send-email-jhs@emojatatu.com> <20170419125336.GC3357@nanopsycho.orion> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Cc: davem@davemloft.net, netdev@vger.kernel.org, eric.dumazet@gmail.com, xiyou.wangcong@gmail.com To: Jiri Pirko Return-path: Received: from mail-it0-f67.google.com ([209.85.214.67]:34769 "EHLO mail-it0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934273AbdDSNL3 (ORCPT ); Wed, 19 Apr 2017 09:11:29 -0400 Received: by mail-it0-f67.google.com with SMTP id 193so2728844itm.1 for ; Wed, 19 Apr 2017 06:11:28 -0700 (PDT) In-Reply-To: <20170419125336.GC3357@nanopsycho.orion> Sender: netdev-owner@vger.kernel.org List-ID: On 17-04-19 08:53 AM, Jiri Pirko wrote: > Wed, Apr 19, 2017 at 01:57:30PM CEST, jhs@mojatatu.com wrote: >> From: Jamal Hadi Salim >> >> This adds support for filtering based on time since last used. >> When we are dumping a large number of actions it is useful to >> have the option of filtering based on when the action was last >> used to reduce the amount of data crossing to user space. >> >> With this patch the user space app sets the TCAA_ACT_TIME_FILTER >> attribute with the value in milliseconds with "time of interest >> since now". The kernel converts this to jiffies and does the >> filtering comparison matching entries that have seen activity >> since then and returns them to user space. >> Old kernels and old tc continue to work in legacy mode since >> they dont specify this attribute. >> >> Some example (we have 400 actions bound to 400 filters); at installation >> time using hacked tc which sets the time of interest to 120 seconds: >> >> prompt$ hackedtc actions ls action gact | grep index | wc -l >> 400 >> >> go get some coffee and wait for > 120 seconds and try again: >> >> prompt$ hackedtc actions ls action gact | grep index | wc -l >> 0 >> >> Lets see a filter bound to one of these actions: >> .. >> filter pref 10 u32 >> filter pref 10 u32 fh 800: ht divisor 1 >> filter pref 10 u32 fh 800::800 order 2048 key ht 800 bkt 0 flowid 1:10 (rule hit 2 success 1) >> match 7f000002/ffffffff at 12 (success 1 ) >> action order 1: gact action pass >> random type none pass val 0 >> index 23 ref 2 bind 1 installed 1145 sec used 802 sec >> Action statistics: >> Sent 84 bytes 1 pkt (dropped 0, overlimits 0 requeues 0) >> backlog 0b 0p requeues 0 >> .... >> >> that coffee took long, no? It was good. >> >> Now lets ping -c 1 127.0.0.2, then run the actions again: >> >> prompt$ hackedtc actions ls action gact | grep index | wc -l >> 1 >> >> More details please: >> >> prompt$ hackedtc -s actions ls action gact > > I don't see where you pass the time. > User space sets the TCAA_ACT_TIME_FILTER value. Jiri - this is described in the commit log ;-> I have some tc changes which set this value. In the example below it was 120 seconds. > >> >> action order 0: gact action pass >> random type none pass val 0 >> index 23 ref 2 bind 1 installed 1270 sec used 30 sec >> Action statistics: >> Sent 168 bytes 2 pkt (dropped 0, overlimits 0 requeues 0) >> backlog 0b 0p requeues 0 >> >> And the filter? >> >> filter pref 10 u32 >> filter pref 10 u32 fh 800: ht divisor 1 >> filter pref 10 u32 fh 800::800 order 2048 key ht 800 bkt 0 flowid 1:10 (rule hit 4 success 2) >> match 7f000002/ffffffff at 12 (success 2 ) >> action order 1: gact action pass >> random type none pass val 0 >> index 23 ref 2 bind 1 installed 1324 sec used 84 sec >> Action statistics: >> Sent 168 bytes 2 pkt (dropped 0, overlimits 0 requeues 0) >> backlog 0b 0p requeues 0 >> >> Signed-off-by: Jamal Hadi Salim >> --- >> include/uapi/linux/rtnetlink.h | 1 + >> net/sched/act_api.c | 25 +++++++++++++++++++++++-- >> 2 files changed, 24 insertions(+), 2 deletions(-) >> >> diff --git a/include/uapi/linux/rtnetlink.h b/include/uapi/linux/rtnetlink.h >> index c7080ec..1b36cc0 100644 >> --- a/include/uapi/linux/rtnetlink.h >> +++ b/include/uapi/linux/rtnetlink.h >> @@ -680,6 +680,7 @@ enum { >> TCAA_ACT_TAB, >> TCAA_ACT_FLAGS, >> TCAA_ACT_COUNT, >> + TCAA_ACT_TIME_FILTER, > > Another use of word "filter" for something else. I believe that we need > to reduce confusion, not to make it worse. > It is a time filter. What do you want to call it? > >> __TCAA_MAX >> }; >> >> diff --git a/net/sched/act_api.c b/net/sched/act_api.c >> index 45e1cf7..b03863a 100644 >> --- a/net/sched/act_api.c >> +++ b/net/sched/act_api.c >> @@ -84,11 +84,12 @@ static int tcf_dump_walker(struct tcf_hashinfo *hinfo, struct sk_buff *skb, >> { >> int err = 0, index = -1, i = 0, s_i = 0, n_i = 0; >> unsigned short act_flags = cb->args[2]; >> + unsigned long jiffy_filter = cb->args[3]; > > call this "jiffy_since" for example > Sure. > >> struct nlattr *nest; >> >> spin_lock_bh(&hinfo->lock); >> >> - s_i = cb->args[0]; >> + s_i = cb->args[4]; >> >> for (i = 0; i < (hinfo->hmask + 1); i++) { >> struct hlist_head *head; >> @@ -101,6 +102,11 @@ static int tcf_dump_walker(struct tcf_hashinfo *hinfo, struct sk_buff *skb, >> if (index < s_i) >> continue; >> >> + if (jiffy_filter && >> + time_after(jiffy_filter, >> + (unsigned long)p->tcfa_tm.lastuse)) >> + continue; >> + >> nest = nla_nest_start(skb, n_i); >> if (nest == NULL) >> goto nla_put_failure; >> @@ -118,6 +124,9 @@ static int tcf_dump_walker(struct tcf_hashinfo *hinfo, struct sk_buff *skb, >> } >> } >> done: >> + if (index > 0) >> + cb->args[4] = index + 1; >> + >> spin_unlock_bh(&hinfo->lock); >> if (n_i) { >> cb->args[0] += n_i; > > You don't use "cb->args[0]" anymore. Why do you need this? You are right - will remove this. > Just use cb->args[0] instead of 4 > I can do that too. > >> @@ -1000,6 +1009,7 @@ static int tcf_action_add(struct net *net, struct nlattr *nla, >> >> static const struct nla_policy tcaa_policy[TCAA_MAX + 1] = { >> [TCAA_ACT_FLAGS] = { .type = NLA_U32 }, >> + [TCAA_ACT_TIME_FILTER] = { .type = NLA_U32 }, >> }; >> >> static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n, >> @@ -1090,13 +1100,14 @@ static int tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb) >> struct tcamsg *t = (struct tcamsg *) nlmsg_data(cb->nlh); >> struct nlattr *kind = NULL; >> u32 act_flags = 0; >> + u32 msecs_filter = 0; >> + unsigned long jiffy_wanted = 0; > > Also, "jiffy_since". Same variable, same name please. > np. >> >> ret = nlmsg_parse(cb->nlh, sizeof(struct tcamsg), tcaa, TCAA_MAX, >> tcaa_policy, NULL); >> if (ret < 0) >> return ret; >> >> - > > This should not be part of this patch. > Will remove. > >> kind = find_dump_kind(tcaa); >> if (kind == NULL) { >> pr_info("tc_dump_action: action bad kind\n"); >> @@ -1110,12 +1121,22 @@ static int tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb) >> if (tcaa[TCAA_ACT_FLAGS]) >> act_flags = nla_get_u32(tcaa[TCAA_ACT_FLAGS]); >> >> + if (tcaa[TCAA_ACT_TIME_FILTER]) >> + msecs_filter = nla_get_u32(tcaa[TCAA_ACT_TIME_FILTER]); >> + >> nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq, >> cb->nlh->nlmsg_type, sizeof(*t), 0); >> if (!nlh) >> goto out_module_put; >> >> + if (msecs_filter) { >> + unsigned long jiffy_msecs = msecs_to_jiffies(msecs_filter); >> + >> + jiffy_wanted = jiffies - jiffy_msecs; > > you can do just: > jiffy_wanted = jiffies - msecs_to_jiffies(msecs_filter); > > Also, you can put this under "if (tcaa[TCAA_ACT_TIME_FILTER])" so it's > all in one place. > Will do - next cycle run. cheers, jamal