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 4ABEE46DE2; Tue, 26 Aug 2025 13:55:07 +0200 (CEST) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id F3114402AE; Tue, 26 Aug 2025 13:55:06 +0200 (CEST) Received: from mail-qv1-f49.google.com (mail-qv1-f49.google.com [209.85.219.49]) by mails.dpdk.org (Postfix) with ESMTP id 840374021E for ; Tue, 26 Aug 2025 13:55:05 +0200 (CEST) Received: by mail-qv1-f49.google.com with SMTP id 6a1803df08f44-70ddadde48fso525016d6.0 for ; Tue, 26 Aug 2025 04:55:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=uetpeshawar-edu-pk.20230601.gappssmtp.com; s=20230601; t=1756209305; x=1756814105; 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=A1EilSW0TJO3eMrrYhIHwgV+7oD/Blw9zG8olH+flsA=; b=WJ/cQH2KVUULka+jY/SrRhXO81DOdI6qcYu90Fgx81etXr4Gv9LpS3hFeTiuuMbLt8 webaLCB8BCEP/jhibw6oI5vemJgeLaPASBhXxTOpDAj7w8QWuZhWABtU+RNRg9TzpTsc SaEX1/wUb8NTev0QabxO/FMcLpYa3rTUANbMYZebWjPj4EY/6xoBCapWQU1sZf3YdvOw 2Ln5CD1v2u545MinfVt6p2T0v5OaGnWERJE1tO3EzCYNgz83Ku+v24IXNy9JJtzk9GYc pbVyaC+tE3+MjBHNusQv2rVJtBp5CbAW1ZCLC1e2E1QBny/R4D+SL64Y6TFjKWPVg600 T3yA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1756209305; x=1756814105; 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=A1EilSW0TJO3eMrrYhIHwgV+7oD/Blw9zG8olH+flsA=; b=WM+kaxrXNPiQP+ops981raHSw6rlv8mNPK61L9Gb5t0jpUFm2UZn/6mGlC8R749Jwt 4OrvtmKyBnbU5Mntl7xwbkXn5M+awQ+h0oChppFSrDHG0cIBn8EYsp2xNxW36kAsXvCK O+S/54hqZnPsTQ5MRFDJZmIBN8+OF2jRtu7d0dACuH851SDv3JNHGS5PI/CGXOuu1a4S XsKdbHiKNxuhYatfmIH765NgIXZnYQIx/mmaQrw6/S6GPfPpD9skYFTru4fJ1yLo+9ru 9Cmi61/InJt9JUhQmeSeyQS2u8lzk7HA+Kh5GrZnNgcByTPh0uav/ctH/qDZ+awPyNSL BpwA== X-Forwarded-Encrypted: i=1; AJvYcCX/3aGNcZqkbMpJYP6fKgVqXpBCEy/V/KFr2rtC4CljZ1ETQL4UWT+rrK2dncRWwl+Efzg=@dpdk.org X-Gm-Message-State: AOJu0YwSYlqVzpDoxcUyrJ4pE8lAcUlxhfhTPYS2VALYXruqxHfucQ7T yPevIg4La6i/tLguEWLcL0/bnvqAdGaXGpLzdMDPipuAZx3lBiwO6xN4jHVzAhqGb04ALRldJXm gjUsK/4YvoHgIiOeqnu1guTrNeuidiQ+fQkJt9ZGtHZDr3jNlHjsr4vc= X-Gm-Gg: ASbGncsNyVPHzVX8P7dIbLEFv1RpNO7zThnRejAAmF+JsqFFFrFiluQnNvGHF4YaqOu 3qhcCIokk4AIAy3U50T1ONXf/fS8v9nqvP9lQxd+IZFpbrwN2vPXd7PJdeALt3QzOIqdYFV6KRG kXxStF0pQ882QF8p/wPCKBWv+0XnMbowx9NH5S+JRvt9RxEFbzhRfEuwIQDgEez189/XQ71j7gY +KEZ6vKa+eA2bmp3LPQP7shzrCNIJMg73evM71vuUzi8XlE8HoIuKB++l5fDHX0dNqPS8fTZ5kM 5TOIBzNLXQ== X-Google-Smtp-Source: AGHT+IFW2WOkthHea8qaXH7jvjNBWmF/uSjZgGZ1ceOYd4FrVlXhiqyMGoxR2f0xb/gT0tBKKrdG6q6NKCmLLB1/q6U= X-Received: by 2002:a05:6214:f25:b0:70d:961c:bb05 with SMTP id 6a1803df08f44-70d9709624cmr183104506d6.10.1756209304739; Tue, 26 Aug 2025 04:55:04 -0700 (PDT) MIME-Version: 1.0 References: <20250825123548.1177090-1-ciara.loftus@intel.com> <20250825123548.1177090-4-ciara.loftus@intel.com> In-Reply-To: From: Khadem Ullah <14pwcse1224@uetpeshawar.edu.pk> Date: Tue, 26 Aug 2025 16:54:53 +0500 X-Gm-Features: Ac12FXycqkCBDqAs8493-XRVfCyFp0mZNa_8YXyJ2raJ3f9B1ioocojNamOOQAM Message-ID: Subject: Re: [PATCH 3/4] net/ice: remove SSE vector path To: Bruce Richardson Cc: Ciara Loftus , dev@dpdk.org Content-Type: multipart/alternative; boundary="000000000000c2b925063d4357d7" 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 --000000000000c2b925063d4357d7 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Tue, Aug 26, 2025 at 3:50=E2=80=AFPM Bruce Richardson wrote: > > > No problem. > > BTW: Please don't top-post in replying - it's best practice to put > > the reply below the text you are replying to. Thanks. > > Ohh, I got it :) > I was triming the quotes when replying but in top-post format, > will always try to avoid top-post in replying in future! > > > AVX2 was first available in systems starting in 2013, (and AMD systems > > since 2015), so at this point it's been around a long time. The SSE cod= e > > paths in the drivers will only be used by systems which do not have AVX= 2 > on > > them - which should be relatively rare, I hope, at this point. There ar= e > no > > features in the SSE driver that are not available in the AVX2 one, so, > I'm > > not aware of any reason why one would need to use the SSE code path in = a > > deployment of DPDK. > > Yes, I think all feaures in SSE do already exists in AVX2 paths. > > > Even without this patch, there will be no features added to the SSE cod= e > > paths in the drivers. Any new additions would just be to the AVX2 and > > AVX-512 code paths. Even for systems without AVX2, if the SSE path is > > removed the driver will fall-back to the scalar paths, which have far > more > > features available in them than the SSE codepaths, which were simplifie= d > for > > performance reasons. > > Thanks for the update. I could not exaclty got the meaning of fall-back t= o > the scalar path. > Does that means that the driver automatically switches to the scalar path > ? > which is slower but includes all the necessary features that were > simplified in the AVX2 path. > I believe AVX2 provides an average performance much better for small fram= e > or packet size (about 14 Gbps). > > Reagards, > Khadem > > > -- --000000000000c2b925063d4357d7 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable


On Tue, Aug 26,= 2025 at 3:50=E2=80=AFPM Bruce Richardson <bruce.richardson@intel.com> wrote:

> No problem. <= br>> BTW: Please don't top-post in replying - it's best practice= to put
> the reply below the text you are replying to. Thanks.
Ohh, I got it :)=C2=A0=C2=A0
I was triming the quotes when reply= ing but in top-post format,=C2=A0
will always try to avoid top-pos= t in replying in future!=C2=A0
=C2=A0
> AVX2 was first a= vailable in systems starting in 2013, (and AMD systems
> since 2015),= so at this point it's been around a long time. The SSE code
> pa= ths in the drivers will only be used by systems which do not have AVX2 on> them - which should be relatively rare, I hope, at this point. There= are no
> features in the SSE driver that are not available in the AV= X2 one, so, I'm
> not aware of any reason why one would need to u= se the SSE code path in a
> deployment of DPDK.

Yes, I think all feaures in SSE do already exists in AVX2 paths.=C2= =A0 =C2=A0

> Even without this patch, there will be no features added to the SS= E code
> paths in the drivers. Any new additions would just be to the= AVX2 and
> AVX-512 code paths. Even for systems without AVX2, if the= SSE path is
> removed the driver will fall-back to the scalar paths,= which have far more
> features available in them than the SSE codepa= ths, which were simplified for
> performance reasons.

Thanks for the update. I could not exaclty got the meaning of fall-back = to the scalar path.=C2=A0
Does that means=C2=A0that = the driver automatically switches to the scalar path ?
which is slower b= ut includes all the necessary features that were simplified in the AVX2 pat= h.=C2=A0=C2=A0
I believe AVX2 provides an average performa= nce much better for small frame or packet size (about 14 Gbps).=C2=A0
Reagards,
Khadem=C2=A0




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