From mboxrd@z Thu Jan 1 00:00:00 1970 From: 'Marek =?utf-8?Q?Marczykowski-G=C3=B3recki'?= Subject: Re: [PATCH] libvchan: create xenstore entries in one transaction Date: Wed, 31 Oct 2018 11:43:13 +0100 Message-ID: <20181031104313.GB32486@mail-itl> References: <20181030234905.26142-1-marmarek@invisiblethingslab.com> <20181031101703.emdlgaazvxsyq6jg@zion.uk.xensource.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============2426532845325980101==" Return-path: Received: from us1-rack-dfw2.inumbo.com ([104.130.134.6]) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1gHny3-0003a8-1J for xen-devel@lists.xenproject.org; Wed, 31 Oct 2018 10:43:19 +0000 In-Reply-To: <20181031101703.emdlgaazvxsyq6jg@zion.uk.xensource.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" To: Wei Liu Cc: "xen-devel@lists.xenproject.org" , Paul Durrant , Ian Jackson List-Id: xen-devel@lists.xenproject.org --===============2426532845325980101== Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="IrhDeMKUP4DT/M7F" Content-Disposition: inline --IrhDeMKUP4DT/M7F Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Oct 31, 2018 at 10:17:03AM +0000, Wei Liu wrote: > On Wed, Oct 31, 2018 at 10:08:26AM +0000, Paul Durrant wrote: > > > -----Original Message----- > > > From: Xen-devel [mailto:xen-devel-bounces@lists.xenproject.org] On Be= half > > > Of Marek Marczykowski-G=C3=B3recki > > > Sent: 30 October 2018 23:49 > > > To: xen-devel@lists.xenproject.org > > > Cc: Wei Liu ; Ian Jackson ; > > > Marek Marczykowski-G=C3=B3recki > > > Subject: [Xen-devel] [PATCH] libvchan: create xenstore entries in one > > > transaction > > >=20 > > > This will prevent race when client waits for server with xs_watch - a= ll > > > entries should appear at once. > >=20 > > Watches should be put on the "state" key to avoid this kind of thing. T= hat key should always be the last thing modified and hence there should nev= er really be the need for xenstore transactions at all. >=20 > AIUI libxenvchan doesn't have a "state" key. We can introduce one now > but we still need to handle old code which doesn't know about the new > key. Wei is right, there is no "state" key in libxenvchan. --=20 Best Regards, Marek Marczykowski-G=C3=B3recki Invisible Things Lab A: Because it messes up the order in which people normally read text. Q: Why is top-posting such a bad thing? --IrhDeMKUP4DT/M7F Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEhrpukzGPukRmQqkK24/THMrX1ywFAlvZh0EACgkQ24/THMrX 1yxbRwf9EqyrNjc4THZLMiOfEuN723bhpnPghFdwoHeQua1bOex841uPSneMzpgt Xyf51DDW2Y8WVeDGMQfW8k6L0jLa7FBLGvi0HqGswH/cOs/RDas6y0zoh/KACLx9 fXqeke/Kr8wmZeYHJcKpUrqT4RgLhOLffcq3ci9yUSGyLOSBmHNxDNm/b3ijTk4E BYbGPeLptkOwx22ynXxuaz39vjalFn0z5Cl2T6hoswEAGEir51y6sAkPhDLq1ucL 7h3+MS+n4EWniCvQqCj/7c4bpIQan4khPZfNc5zJStvobNkh/+agIZGRTK2zeRQ4 CKQ4HQ5emrgcNM+Ix8zcENIWG6dKQw== =BcSr -----END PGP SIGNATURE----- --IrhDeMKUP4DT/M7F-- --===============2426532845325980101== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Content-Disposition: inline X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KWGVuLWRldmVs IG1haWxpbmcgbGlzdApYZW4tZGV2ZWxAbGlzdHMueGVucHJvamVjdC5vcmcKaHR0cHM6Ly9saXN0 cy54ZW5wcm9qZWN0Lm9yZy9tYWlsbWFuL2xpc3RpbmZvL3hlbi1kZXZlbA== --===============2426532845325980101==--