From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from gandalf.ozlabs.org (mail.ozlabs.org [IPv6:2404:9400:2221:ea00::3]) by passt.top (Postfix) with ESMTPS id B74EB5A0270 for ; Tue, 18 Oct 2022 14:08:14 +0200 (CEST) Received: by gandalf.ozlabs.org (Postfix, from userid 1007) id 4MsCLH4xpHz4xGm; Tue, 18 Oct 2022 23:08:07 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gibson.dropbear.id.au; s=201602; t=1666094887; bh=VZhbYyfrs+IZdssU50JLtdyIu0ETEOYllfMue7f5u7M=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=VStHwbEKT9EXiJB2H2DV8h3RCJs813RMVO6PvOZG3dnUr+8SXae41G+j6yyp9L8IJ Izpj7Wpe/tnW2N+HXqAVMICPHZ7RwoKJ9hkBa2msTKUc28THIL3MBPbFptuvo4ymwA GKp92GllxBlmjM/WHqyrTcw1hYNVg3N2MJIRc+yU= Date: Tue, 18 Oct 2022 23:07:29 +1100 From: David Gibson To: Stefano Brivio Subject: Re: [PATCH 08/14] tap: Remove unhelpeful vnet_pre optimization from tap_send() Message-ID: References: <20221017085807.473470-1-david@gibson.dropbear.id.au> <20221017085807.473470-9-david@gibson.dropbear.id.au> <20221018050513.04fae95b@elisabeth> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="j9NKKST7E7Zs69Zq" Content-Disposition: inline In-Reply-To: <20221018050513.04fae95b@elisabeth> Message-ID-Hash: X3ZZAAGX3S2E3V7VDPG2LRFG6ZYH565A X-Message-ID-Hash: X3ZZAAGX3S2E3V7VDPG2LRFG6ZYH565A X-MailFrom: dgibson@gandalf.ozlabs.org X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: passt-dev@passt.top X-Mailman-Version: 3.3.3 Precedence: list List-Id: Development discussion and patches for passt Archived-At: <> Archived-At: List-Archive: <> List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: --j9NKKST7E7Zs69Zq Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Oct 18, 2022 at 05:05:13AM +0200, Stefano Brivio wrote: > On Mon, 17 Oct 2022 19:58:01 +1100 > David Gibson wrote: >=20 > > Callers of tap_send() can optionally use a small optimization by adding > > extra space for the 4 byte length header used on the qemu socket interf= ace. > > tap_ip_send() is currently the only user of this, but this is used only > > for "slow path" ICMP and DHCP packets, so there's not a lot of value to > > the optimization. >=20 > Not anymore, definitely. It used to look quite bad in perf(1) when I > shuffled connection data around. Yeah. In any case I think I can get an equivalent optimization back at some point. --=20 David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson --j9NKKST7E7Zs69Zq Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEoULxWu4/Ws0dB+XtgypY4gEwYSIFAmNOlvoACgkQgypY4gEw YSI4bg//TQSGaYLaM7CYyEO48vCJz/vgqBJBhsT1fBjMQzzRFUffVMwRoIL5TNSm pOM1SaDp7dXf272wRtzMrta+JEnDlEHCyu24ajbwGeKJjZmD4TMztagWDeepIZS1 El/jQQ3Dv6Ucy8SjhGtDOPGABFNM90FQ6Ym89SoJ891RtoqEdvut/Kp/yMTVNwXt HKsUU0S3koFXYahtKJi2duYOpfzWWwzztt3BAYbulFxVxme6ycDU2Ctx7DE5lDv/ MagcuFsUVPoJsXsCeL9HBIPsg7ombMtRN6U3CkpdlQCyc1C6jGiMDtmyCQi1GzBz 3B5e8IK3fTDI4tndU1BF3m64Zeq+32uoik9DMIc2Udf4Kxnip4GbBKniRdLmrBuQ O8Qrk61yAyBnIEo9wjFYeINK0CptzeDDnrFLfSSYiziVSQgUXUWkwXHgZ4rmj86e NT1atuydPw5RE92gXdUGwweq/7x0m+yZ6z9QOyVTlaEKKTzD1ehhHo0zie7JqNlD plMWieJ85+pCczju7DbQXyxgOyGpY8r6Wnq6IJm7UhR0rrJtHiUefA+iqsSTq9u9 gC77tkzuOwGQyedQZ98FdpnfugCt0zSRGIgh3CTuwJKlCg85A2FKswTj6NmkAugp 326oEBX5383N7bs9tB1oJdwmnlaBVSFQxm+svGokNkvaFQLoNYg= =7zCP -----END PGP SIGNATURE----- --j9NKKST7E7Zs69Zq--