From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 3737043B74; Thu, 22 Feb 2024 13:39:27 +0100 (CET) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 0BD73402CE; Thu, 22 Feb 2024 13:39:27 +0100 (CET) Received: from mail-oa1-f45.google.com (mail-oa1-f45.google.com [209.85.160.45]) by mails.dpdk.org (Postfix) with ESMTP id 7C20D40281 for ; Thu, 22 Feb 2024 13:39:25 +0100 (CET) Received: by mail-oa1-f45.google.com with SMTP id 586e51a60fabf-21e7c3e3cf3so4601102fac.0 for ; Thu, 22 Feb 2024 04:39:25 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1708605565; x=1709210365; darn=dpdk.org; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=YZj8kh0pSu83arWt+yNXEatim/9FulTftCX2zDPComo=; b=VT9DDLUF6dHyLLVxRIo9gkFBAmnLuTqPBhWhq/41xKNE2XYY4iKyt7el/fouij+89i 0AOCbnR6lWwtwK8jOqK83U3d4XY0X01WsPMH3uyP8SObfwJojGn+v1osOsF9zu9d7E+4 OrorClCKn1cySZw4DjkF3qJLar64121FUZwg575Lon3uGrWTjkjMGgM7iQsKf//p0xiP P0YMNuKjRh9trxHig1KI54q8vE9aaAMh47E8q6IryAysNxc3tm4D+qleoucbcT5+Ukd4 d4/JzgYCPVu9h3/FJq+jk7Z711Ft9Ltm9kqxYCYTI9sxZpFgBHezgr9ic3Zu/3FrgADd 5GLQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1708605565; x=1709210365; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=YZj8kh0pSu83arWt+yNXEatim/9FulTftCX2zDPComo=; b=SMiKtX078RoeCPhWQbyvVMmxdHBl+Xv0H0S2kzX7ApgCo3hkBE6Lv9Cd91NRGsOUXF 1BxpRDFj4rJqEAuEu3u5MK+5Y1QW+pYsy5lnNMMxwbGlbc0OF2224NUZqSFvwDeqHzcv PrgiwFnyAG4H9A72EpFLN7aFe1jKWKHSla8+m2/EL5wApxVEv4UF3qWmSN3OQ06HGkFK bmzaGpPzGFEA2up3hC3g6Ks3It0sjPElyTlTuuqhrWE803odxKpVLWVWaen9eOwCR9/x Cfb/K6AZdk6nRiOg0huMTkr2CDqnG9ltIaZCA5jHMf/mT+DXYYzNN3/ODNZGJVWPVevH VKEQ== X-Forwarded-Encrypted: i=1; AJvYcCWwsfoxN7LH8a8fNZrAXxijHsBxS8S1PuzCUSZhFUxsOZxCKj1LJN/jdBlSX6YTgRLpeEZ5GfWu8bA48WE= X-Gm-Message-State: AOJu0Yy/1fm4s52rW8iV8rf8WLXD4cZEMLJvpXpWsrUbwRxrcCchx13l 7xOyO2SVT6bVHl26pX9SagnrGtH7vtBoTAQiQpgh5i9fl63pJqvhO8VYbbl27jvZtJlfi8I9aB8 drgkwdKi/96XNA/IM+EatplBbGSw= X-Google-Smtp-Source: AGHT+IE1RFWfW5bqobtDF8ApI7Jog2e79H/n4+sfhQHY7tglNHh+TyCrEEHdUCHwv++z2MTiCyBnP+Yw5HVWa3pfppY= X-Received: by 2002:a05:6870:56a5:b0:21e:5ba8:ebb7 with SMTP id p37-20020a05687056a500b0021e5ba8ebb7mr19088706oao.27.1708605564581; Thu, 22 Feb 2024 04:39:24 -0800 (PST) MIME-Version: 1.0 References: <20240207153340.34146-1-aomeryamac@gmail.com> <4CC50196-1F8F-40E2-8280-261783FDCFC8@arm.com> <772E05E7-716C-4A41-8C75-7323D9D745BC@arm.com> In-Reply-To: <772E05E7-716C-4A41-8C75-7323D9D745BC@arm.com> From: =?UTF-8?B?QWJkdWxsYWggw5ZtZXIgWWFtYcOn?= Date: Thu, 22 Feb 2024 15:39:13 +0300 Message-ID: Subject: Re: [PATCH] lib/hash,lib/rcu: feature hidden key count in hash To: Honnappa Nagarahalli Cc: "Medvedkin, Vladimir" , "dev@dpdk.org" , Yipeng Wang , Sameh Gobriel , Bruce Richardson , "thomas@monjalon.net" , nd Content-Type: multipart/alternative; boundary="000000000000bcfabf0611f7bbf5" X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org --000000000000bcfabf0611f7bbf5 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable As a final decision, I will add a new hash API that forces the reclaim. Is it ok for everyone? On Thu, Feb 22, 2024 at 5:37=E2=80=AFAM Honnappa Nagarahalli < Honnappa.Nagarahalli@arm.com> wrote: > > > > On Feb 21, 2024, at 3:51=E2=80=AFPM, Abdullah =C3=96mer Yama=C3=A7 > wrote: > > > > > > > > On Wed, Feb 21, 2024 at 6:24=E2=80=AFAM Honnappa Nagarahalli < > Honnappa.Nagarahalli@arm.com> wrote: > > > > > > > On Feb 20, 2024, at 12:58=E2=80=AFPM, Abdullah =C3=96mer Yama=C3=A7 < > aomeryamac@gmail.com> wrote: > > > > > > I appreciate that you gave me suggestions and comments. I will make > changes according to all your recommendations, but before that, I want to > make everyone's minds clear. Then, I will apply modifications. > > > > > > On Tue, Feb 20, 2024 at 2:35=E2=80=AFAM Honnappa Nagarahalli < > Honnappa.Nagarahalli@arm.com> wrote: > > > > > > > > > > On Feb 19, 2024, at 3:28=E2=80=AFPM, Abdullah =C3=96mer Yama=C3=A7 = < > aomeryamac@gmail.com> wrote: > > > > > > > > Hello, > > > > > > > > Let me explain a use case; > > > > > > > > I have a hash table whose key value is IP addresses, and data (let'= s > say the username of the IP) is related to the IP address. The key point i= s > matching these data with flows. Flows are dynamic, and this hash table is > dynamic, as well; both can change anytime. For example, when a flow start= s, > we look up the hash table with the corresponding IP and retrieve the > username. We need to hold this username until the flow terminates, althou= gh > we removed this IP key from the hash table (multithread). That's why we > have RCU and defer queue is necessary for high performance. In my > application, I need to know the number of IP-username entries. These > numbers can be calculated by rte_hash_count - defer queue size. > > > The entries in the defer queue are not reclaimed (there is a > probability that all of them can be reclaimed) and hence they are not > available for allocation. So, rte_hash_count - defer queue size might not > give you the correct number you are expecting. > > > > > > Currently, there is no API in hash library that forces a reclaim. Doe= s > it makes sense to have an API that just does the reclaim (and returns the > number of entries pending in the defer queue)? A call to rte_hash_count > should provide the exact count you are looking for. > > > You are right; no API in the hash library forces a reclaim. In my > application, I periodically call rte_count to retrieve hash size, and thi= s > data is shown in my GUI. So that means I need to call regularly reclaim. = I > am trying to figure out which is better, calling reclaim or retrieving th= e > defer queue size. Any comment about this? > > Retrieving the defer queue size will be cheaper. However, calling the > reclaim API will ensure the entries are freed hence providing an accurate > number. Calling the reclaim API on an empty defer queue does not consume > many cycles. If needed we could add a check for empty defer queue in the > reclaim API and return early. > > > > I am also wondering if a reclaim API in hash library is needed. Why not > call rte_rcu_qsbr_dq_reclaim API from the application? > > The reason is simple. struct rte_hash *h is an internal structure and w= e > cannot access the h->dq. So it is not possible to call reclaim. > Ack. This will be just a wrapper around the rte_rcu_qsbr_dq_reclaim. > > > > > > > > > > > > > I think if you need a non-blocking and multithreaded hash table, an > RCU-enabled hash table is necessary. Also, this API is necessary if you > need to get the actual matchable size. > > > > > > > > > > > > > > > > > > > > > > > > On Mon, Feb 19, 2024 at 8:36=E2=80=AFPM Medvedkin, Vladimir < > vladimir.medvedkin@intel.com> wrote: > > > > Hi Abdullah, > > > > > > > > Could you please tell more about use cases where this API may be > useful? > > > > > > > > >a new API to get the hidden key count in the hash table if the rcu > qsbr is enabled > > > > > > > > Here in commit message and down below in doxygen comments, I think > this > > > > statement should be more specific because rcu can be created with > > > > RTE_HASH_QSBR_MODE_SYNC mode i.e. without defer queue. > > > > > > > > Also, new API must be reflected in release notes > > > > > > > > On 07/02/2024 15:33, Abdullah =C3=96mer Yama=C3=A7 wrote: > > > > > This patch introduce a new API to get the hidden key count in the > hash > > > > > table if the rcu qsbr is enabled. When using rte_hash_count with > rcu > > > > > qsbr enabled, it will return the number of elements that are not > in the > > > > > free queue. Unless rte_rcu_qsbr_dq_reclaim is called, the number = of > > > > > elements in the defer queue will not be counted and freed. > Therefore I > > > > > added a new API to get the number of hidden (defer queue) element= s > > > > > in the hash table. Then the user can calculate the total number o= f > > > > > elements that are available in the hash table. > > > > > > > > > > Signed-off-by: Abdullah =C3=96mer Yama=C3=A7 > > > > > > > > > > --- > > > > > Cc: Honnappa Nagarahalli > > > > > Cc: Yipeng Wang > > > > > Cc: Sameh Gobriel > > > > > Cc: Bruce Richardson > > > > > Cc: Vladimir Medvedkin > > > > > --- > > > > > lib/hash/rte_cuckoo_hash.c | 9 +++++++++ > > > > > lib/hash/rte_hash.h | 13 +++++++++++++ > > > > > lib/hash/version.map | 1 + > > > > > lib/rcu/rte_rcu_qsbr.c | 8 ++++++++ > > > > > lib/rcu/rte_rcu_qsbr.h | 11 +++++++++++ > > > > > lib/rcu/version.map | 1 + > > > > > 6 files changed, 43 insertions(+) > > > > > > > > > > diff --git a/lib/hash/rte_cuckoo_hash.c > b/lib/hash/rte_cuckoo_hash.c > > > > > index 70456754c4..3553f3efc7 100644 > > > > > --- a/lib/hash/rte_cuckoo_hash.c > > > > > +++ b/lib/hash/rte_cuckoo_hash.c > > > > > @@ -555,6 +555,15 @@ rte_hash_max_key_id(const struct rte_hash *h= ) > > > > > return h->entries; > > > > > } > > > > > > > > > > +int32_t > > > > > +rte_hash_dq_count(const struct rte_hash *h) > > > > > +{ > > > > > + if (h->dq =3D=3D NULL) > > > > input arguments must be checked since this is a public API, the sam= e > is > > > > true for rte_rcu_qsbr_dq_count() > > > > > + return -EINVAL; > > > > why not just return 0? > > > > > + > > > > > + return rte_rcu_qsbr_dq_count(h->dq); > > > > > +} > > > > > + > > > > > int32_t > > > > > rte_hash_count(const struct rte_hash *h) > > > > > { > > > > > diff --git a/lib/hash/rte_hash.h b/lib/hash/rte_hash.h > > > > > index 7ecc021111..8ea97e297d 100644 > > > > > --- a/lib/hash/rte_hash.h > > > > > +++ b/lib/hash/rte_hash.h > > > > > @@ -193,6 +193,19 @@ rte_hash_free(struct rte_hash *h); > > > > > void > > > > > rte_hash_reset(struct rte_hash *h); > > > > > > > > > > + > > > > > +/** > > > > > + * Return the number of records in the defer queue of the hash > table > > > > > + * if RCU is enabled. > > > > > + * @param h > > > > > + * Hash table to query from > > > > > + * @return > > > > > + * - -EINVAL if parameters are invalid > > > > > + * - A value indicating how many records were inserted in the > table. > > > > did you mean how many records are kept in defer queue? > > > > > + */ > > > > > +int32_t > > > > > +rte_hash_dq_count(const struct rte_hash *h); > > > > > + > > > > > /** > > > > > * Return the number of keys in the hash table > > > > > * @param h > > > > > diff --git a/lib/hash/version.map b/lib/hash/version.map > > > > > index 6b2afebf6b..7f7b158cf1 100644 > > > > > --- a/lib/hash/version.map > > > > > +++ b/lib/hash/version.map > > > > > @@ -9,6 +9,7 @@ DPDK_24 { > > > > > rte_hash_add_key_with_hash; > > > > > rte_hash_add_key_with_hash_data; > > > > > rte_hash_count; > > > > > + rte_hash_dq_count; > > > > new API must introduced as an experimental API. The same is true fo= r > > > > rte_rcu_qsbr_dq_count() > > > > > rte_hash_crc32_alg; > > > > > rte_hash_crc_set_alg; > > > > > rte_hash_create; > > > > > diff --git a/lib/rcu/rte_rcu_qsbr.c b/lib/rcu/rte_rcu_qsbr.c > > > > > index bd0b83be0c..89f8da4c4c 100644 > > > > > --- a/lib/rcu/rte_rcu_qsbr.c > > > > > +++ b/lib/rcu/rte_rcu_qsbr.c > > > > > @@ -450,6 +450,14 @@ rte_rcu_qsbr_dq_reclaim(struct > rte_rcu_qsbr_dq *dq, unsigned int n, > > > > > return 0; > > > > > } > > > > > > > > > > +/** > > > > > + * Return the number of entries in a defer queue. > > > > > + */ > > > > > +unsigned int rte_rcu_qsbr_dq_count(struct rte_rcu_qsbr_dq *dq) > > > > > +{ > > > Please validate dq here. > > > > > > > > + return rte_ring_count(dq->r); > > > > > +} > > > > > + > > > > > /* Delete a defer queue. */ > > > > > int > > > > > rte_rcu_qsbr_dq_delete(struct rte_rcu_qsbr_dq *dq) > > > > > diff --git a/lib/rcu/rte_rcu_qsbr.h b/lib/rcu/rte_rcu_qsbr.h > > > > > index 23c9f89805..ed5a590edd 100644 > > > > > --- a/lib/rcu/rte_rcu_qsbr.h > > > > > +++ b/lib/rcu/rte_rcu_qsbr.h > > > > > @@ -794,6 +794,17 @@ int > > > > > rte_rcu_qsbr_dq_reclaim(struct rte_rcu_qsbr_dq *dq, unsigned in= t > n, > > > > > unsigned int *freed, unsigned int *pending, unsigned int > *available); > > > > > > > > > > +/** > > > > > + * Return the number of entries in a defer queue. > > > > > + * > > > > > + * @param dq > > > > > + * Defer queue. > > > > > + * @return > > > > > + * The number of entries in the defer queue. > > > > > + */ > > > > > +unsigned int > > > > > +rte_rcu_qsbr_dq_count(struct rte_rcu_qsbr_dq *dq); > > > Agree on the need for this API in RCU > > > > > > > > + > > > > > /** > > > > > * Delete a defer queue. > > > > > * > > > > > diff --git a/lib/rcu/version.map b/lib/rcu/version.map > > > > > index 982ffd59d9..f410ab41e7 100644 > > > > > --- a/lib/rcu/version.map > > > > > +++ b/lib/rcu/version.map > > > > > @@ -5,6 +5,7 @@ DPDK_24 { > > > > > rte_rcu_qsbr_dq_create; > > > > > rte_rcu_qsbr_dq_delete; > > > > > rte_rcu_qsbr_dq_enqueue; > > > > > + rte_rcu_qsbr_dq_count; > > > > > rte_rcu_qsbr_dq_reclaim; > > > > > rte_rcu_qsbr_dump; > > > > > rte_rcu_qsbr_get_memsize; > > > > > > > > -- > > > > Regards, > > > > Vladimir > > > > > > > > > > > --000000000000bcfabf0611f7bbf5 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
As a final decision, I will add a new hash API that forces= the reclaim. Is it ok for everyone?

On Thu, Feb 22, 2024 at 5:37=E2=80=AFAM= Honnappa Nagarahalli <H= onnappa.Nagarahalli@arm.com> wrote:


> On Feb 21, 2024, at 3:51=E2=80=AFPM, Abdullah =C3=96mer Yama=C3=A7 <= ;aomeryamac@gmail= .com> wrote:
>
>
>
> On Wed, Feb 21, 2024 at 6:24=E2=80=AFAM Honnappa Nagarahalli <Honnappa.Nagar= ahalli@arm.com> wrote:
>
>
> > On Feb 20, 2024, at 12:58=E2=80=AFPM, Abdullah =C3=96mer Yama=C3= =A7 <aomeryama= c@gmail.com> wrote:
> >
> > I appreciate that you gave me suggestions and comments. I will ma= ke changes according to all your recommendations, but before that, I want t= o make everyone's minds clear. Then, I will apply modifications.
> >
> > On Tue, Feb 20, 2024 at 2:35=E2=80=AFAM Honnappa Nagarahalli <= Honnappa.= Nagarahalli@arm.com> wrote:
> >
> >
> > > On Feb 19, 2024, at 3:28=E2=80=AFPM, Abdullah =C3=96mer Yama= =C3=A7 <aomery= amac@gmail.com> wrote:
> > >
> > > Hello,
> > >
> > > Let me explain a use case;
> > >
> > > I have a hash table whose key value is IP addresses, and dat= a (let's say the username of the IP) is related to the IP address. The = key point is matching these data with flows. Flows are dynamic, and this ha= sh table is dynamic, as well; both can change anytime. For example, when a = flow starts, we look up the hash table with the corresponding IP and retrie= ve the username. We need to hold this username until the flow terminates, a= lthough we removed this IP key from the hash table (multithread). That'= s why we have RCU and defer queue is necessary for high performance. In my = application, I need to know the number of IP-username entries. These number= s can be calculated by rte_hash_count - defer queue size.
> > The entries in the defer queue are not reclaimed (there is a prob= ability that all of them can be reclaimed) and hence they are not available= for allocation. So, rte_hash_count - defer queue size might not give you t= he correct number you are expecting.
> >
> > Currently, there is no API in hash library that forces a reclaim.= Does it makes sense to have an API that just does the reclaim (and returns= the number of entries pending in the defer queue)? A call to rte_hash_coun= t should provide the exact count you are looking for.
> > You are right; no API in the hash library forces a reclaim. In my= application, I periodically call rte_count to retrieve hash size, and this= data is shown in my GUI. So that means I need to call regularly reclaim. I= am trying to figure out which is better, calling reclaim or retrieving the= defer queue size. Any comment about this?
> Retrieving the defer queue size will be cheaper. However, calling the = reclaim API will ensure the entries are freed hence providing an accurate n= umber. Calling the reclaim API on an empty defer queue does not consume man= y cycles. If needed we could add a check for empty defer queue in the recla= im API and return early.
>
> I am also wondering if a reclaim API in hash library is needed. Why no= t call rte_rcu_qsbr_dq_reclaim API from the application?
> The reason is simple. struct rte_hash *h is an internal structure and = we cannot access the h->dq. So it is not possible to call reclaim.
Ack. This will be just a wrapper around the rte_rcu_qsbr_dq_reclaim.

>
>
> > >
> > > I think if you need a non-blocking and multithreaded hash ta= ble, an RCU-enabled hash table is necessary. Also, this API is necessary if= you need to get the actual matchable size.
> > >
> > >
> > >
> > >
> > >
> > > On Mon, Feb 19, 2024 at 8:36=E2=80=AFPM Medvedkin, Vladimir = <vladi= mir.medvedkin@intel.com> wrote:
> > > Hi Abdullah,
> > >
> > > Could you please tell more about use cases where this API ma= y be useful?
> > >
> > > >a new API to get the hidden key count in the hash table = if the rcu qsbr is enabled
> > >
> > > Here in commit message and down below in doxygen comments, I= think this
> > > statement should be more specific because rcu can be created= with
> > > RTE_HASH_QSBR_MODE_SYNC mode i.e. without defer queue.
> > >
> > > Also, new API must be reflected in release notes
> > >
> > > On 07/02/2024 15:33, Abdullah =C3=96mer Yama=C3=A7 wrote: > > > > This patch introduce a new API to get the hidden key co= unt in the hash
> > > > table if the rcu qsbr is enabled. When using rte_hash_c= ount with rcu
> > > > qsbr enabled, it will return the number of elements tha= t are not in the
> > > > free queue. Unless rte_rcu_qsbr_dq_reclaim is called, t= he number of
> > > > elements in the defer queue will not be counted and fre= ed. Therefore I
> > > > added a new API to get the number of hidden (defer queu= e) elements
> > > > in the hash table. Then the user can calculate the tota= l number of
> > > > elements that are available in the hash table.
> > > >
> > > > Signed-off-by: Abdullah =C3=96mer Yama=C3=A7 <aomeryamac@gmail.com>
> > > >
> > > > ---
> > > > Cc: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>= ;
> > > > Cc: Yipeng Wang <yipeng1.wang@intel.com>
> > > > Cc: Sameh Gobriel <sameh.gobriel@intel.com>
> > > > Cc: Bruce Richardson <bruce.richardson@intel.com>
> > > > Cc: Vladimir Medvedkin <vladimir.medvedkin@intel.com><= br> > > > > ---
> > > >=C2=A0 =C2=A0lib/hash/rte_cuckoo_hash.c |=C2=A0 9 ++++++= +++
> > > >=C2=A0 =C2=A0lib/hash/rte_hash.h=C2=A0 =C2=A0 =C2=A0 =C2= =A0 | 13 +++++++++++++
> > > >=C2=A0 =C2=A0lib/hash/version.map=C2=A0 =C2=A0 =C2=A0 = =C2=A0|=C2=A0 1 +
> > > >=C2=A0 =C2=A0lib/rcu/rte_rcu_qsbr.c=C2=A0 =C2=A0 =C2=A0|= =C2=A0 8 ++++++++
> > > >=C2=A0 =C2=A0lib/rcu/rte_rcu_qsbr.h=C2=A0 =C2=A0 =C2=A0|= 11 +++++++++++
> > > >=C2=A0 =C2=A0lib/rcu/version.map=C2=A0 =C2=A0 =C2=A0 =C2= =A0 |=C2=A0 1 +
> > > >=C2=A0 =C2=A06 files changed, 43 insertions(+)
> > > >
> > > > diff --git a/lib/hash/rte_cuckoo_hash.c b/lib/hash/rte_= cuckoo_hash.c
> > > > index 70456754c4..3553f3efc7 100644
> > > > --- a/lib/hash/rte_cuckoo_hash.c
> > > > +++ b/lib/hash/rte_cuckoo_hash.c
> > > > @@ -555,6 +555,15 @@ rte_hash_max_key_id(const struct r= te_hash *h)
> > > >=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0r= eturn h->entries;
> > > >=C2=A0 =C2=A0}
> > > >=C2=A0 =C2=A0
> > > > +int32_t
> > > > +rte_hash_dq_count(const struct rte_hash *h)
> > > > +{
> > > > +=C2=A0 =C2=A0 =C2=A0if (h->dq =3D=3D NULL)
> > > input arguments must be checked since this is a public API, = the same is
> > > true for rte_rcu_qsbr_dq_count()
> > > > +=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0return= -EINVAL;
> > > why not just return 0?
> > > > +
> > > > +=C2=A0 =C2=A0 =C2=A0return rte_rcu_qsbr_dq_count(h->= ;dq);
> > > > +}
> > > > +
> > > >=C2=A0 =C2=A0int32_t
> > > >=C2=A0 =C2=A0rte_hash_count(const struct rte_hash *h) > > > >=C2=A0 =C2=A0{
> > > > diff --git a/lib/hash/rte_hash.h b/lib/hash/rte_hash.h<= br> > > > > index 7ecc021111..8ea97e297d 100644
> > > > --- a/lib/hash/rte_hash.h
> > > > +++ b/lib/hash/rte_hash.h
> > > > @@ -193,6 +193,19 @@ rte_hash_free(struct rte_hash *h);=
> > > >=C2=A0 =C2=A0void
> > > >=C2=A0 =C2=A0rte_hash_reset(struct rte_hash *h);
> > > >=C2=A0 =C2=A0
> > > > +
> > > > +/**
> > > > + * Return the number of records in the defer queue of = the hash table
> > > > + * if RCU is enabled.
> > > > + * @param h
> > > > + *=C2=A0 Hash table to query from
> > > > + * @return
> > > > + *=C2=A0 =C2=A0- -EINVAL if parameters are invalid
> > > > + *=C2=A0 =C2=A0- A value indicating how many records w= ere inserted in the table.
> > > did you mean how many records are kept in defer queue?
> > > > + */
> > > > +int32_t
> > > > +rte_hash_dq_count(const struct rte_hash *h);
> > > > +
> > > >=C2=A0 =C2=A0/**
> > > >=C2=A0 =C2=A0 * Return the number of keys in the hash ta= ble
> > > >=C2=A0 =C2=A0 * @param h
> > > > diff --git a/lib/hash/version.map b/lib/hash/version.ma= p
> > > > index 6b2afebf6b..7f7b158cf1 100644
> > > > --- a/lib/hash/version.map
> > > > +++ b/lib/hash/version.map
> > > > @@ -9,6 +9,7 @@ DPDK_24 {
> > > >=C2=A0 =C2=A0 =C2=A0 =C2=A0rte_hash_add_key_with_hash; > > > >=C2=A0 =C2=A0 =C2=A0 =C2=A0rte_hash_add_key_with_hash_da= ta;
> > > >=C2=A0 =C2=A0 =C2=A0 =C2=A0rte_hash_count;
> > > > +=C2=A0 =C2=A0 =C2=A0rte_hash_dq_count;
> > > new API must introduced as an experimental API. The same is = true for
> > > rte_rcu_qsbr_dq_count()
> > > >=C2=A0 =C2=A0 =C2=A0 =C2=A0rte_hash_crc32_alg;
> > > >=C2=A0 =C2=A0 =C2=A0 =C2=A0rte_hash_crc_set_alg;
> > > >=C2=A0 =C2=A0 =C2=A0 =C2=A0rte_hash_create;
> > > > diff --git a/lib/rcu/rte_rcu_qsbr.c b/lib/rcu/rte_rcu_q= sbr.c
> > > > index bd0b83be0c..89f8da4c4c 100644
> > > > --- a/lib/rcu/rte_rcu_qsbr.c
> > > > +++ b/lib/rcu/rte_rcu_qsbr.c
> > > > @@ -450,6 +450,14 @@ rte_rcu_qsbr_dq_reclaim(struct rte= _rcu_qsbr_dq *dq, unsigned int n,
> > > >=C2=A0 =C2=A0 =C2=A0 =C2=A0return 0;
> > > >=C2=A0 =C2=A0}
> > > >=C2=A0 =C2=A0
> > > > +/**
> > > > + * Return the number of entries in a defer queue.
> > > > + */
> > > > +unsigned int rte_rcu_qsbr_dq_count(struct rte_rcu_qsbr= _dq *dq)
> > > > +{
> > Please validate dq here.
> >
> > > > +=C2=A0 =C2=A0 =C2=A0return rte_ring_count(dq->r); > > > > +}
> > > > +
> > > >=C2=A0 =C2=A0/* Delete a defer queue. */
> > > >=C2=A0 =C2=A0int
> > > >=C2=A0 =C2=A0rte_rcu_qsbr_dq_delete(struct rte_rcu_qsbr_= dq *dq)
> > > > diff --git a/lib/rcu/rte_rcu_qsbr.h b/lib/rcu/rte_rcu_q= sbr.h
> > > > index 23c9f89805..ed5a590edd 100644
> > > > --- a/lib/rcu/rte_rcu_qsbr.h
> > > > +++ b/lib/rcu/rte_rcu_qsbr.h
> > > > @@ -794,6 +794,17 @@ int
> > > >=C2=A0 =C2=A0rte_rcu_qsbr_dq_reclaim(struct rte_rcu_qsbr= _dq *dq, unsigned int n,
> > > >=C2=A0 =C2=A0 =C2=A0 =C2=A0unsigned int *freed, unsigned= int *pending, unsigned int *available);
> > > >=C2=A0 =C2=A0
> > > > +/**
> > > > + * Return the number of entries in a defer queue.
> > > > + *
> > > > + * @param dq
> > > > + *=C2=A0 =C2=A0Defer queue.
> > > > + * @return
> > > > + *=C2=A0 =C2=A0The number of entries in the defer queu= e.
> > > > + */
> > > > +unsigned int
> > > > +rte_rcu_qsbr_dq_count(struct rte_rcu_qsbr_dq *dq);
> > Agree on the need for this API in RCU
> >
> > > > +
> > > >=C2=A0 =C2=A0/**
> > > >=C2=A0 =C2=A0 * Delete a defer queue.
> > > >=C2=A0 =C2=A0 *
> > > > diff --git a/lib/rcu/version.map b/lib/rcu/version.map<= br> > > > > index 982ffd59d9..f410ab41e7 100644
> > > > --- a/lib/rcu/version.map
> > > > +++ b/lib/rcu/version.map
> > > > @@ -5,6 +5,7 @@ DPDK_24 {
> > > >=C2=A0 =C2=A0 =C2=A0 =C2=A0rte_rcu_qsbr_dq_create;
> > > >=C2=A0 =C2=A0 =C2=A0 =C2=A0rte_rcu_qsbr_dq_delete;
> > > >=C2=A0 =C2=A0 =C2=A0 =C2=A0rte_rcu_qsbr_dq_enqueue;
> > > > +=C2=A0 =C2=A0 =C2=A0rte_rcu_qsbr_dq_count;
> > > >=C2=A0 =C2=A0 =C2=A0 =C2=A0rte_rcu_qsbr_dq_reclaim;
> > > >=C2=A0 =C2=A0 =C2=A0 =C2=A0rte_rcu_qsbr_dump;
> > > >=C2=A0 =C2=A0 =C2=A0 =C2=A0rte_rcu_qsbr_get_memsize;
> > >
> > > --
> > > Regards,
> > > Vladimir
> > >
> >
>

--000000000000bcfabf0611f7bbf5--