From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dario Faggioli Subject: Re: [PATCH 3/7] xen: rework locking for dump of scheduler info (debug-key r) Date: Tue, 17 Mar 2015 11:18:57 +0000 Message-ID: <1426591136.32500.67.camel@citrix.com> References: <20150316165642.10279.86684.stgit@Solace.station> <20150316170509.10279.79362.stgit@Solace.station> <55081607020000780006AAAE@mail.emea.novell.com> <55080A71.1070705@eu.citrix.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============7006069983584452687==" Return-path: In-Reply-To: <55080A71.1070705@eu.citrix.com> Content-Language: en-US List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: George Dunlap Cc: "Keir (Xen.org)" , "xumengpanda@gmail.com" , "JBeulich@suse.com" , "xen-devel@lists.xen.org" List-Id: xen-devel@lists.xenproject.org --===============7006069983584452687== Content-Language: en-US Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-TZmWlXqiM+5YBwPzGGny" --=-TZmWlXqiM+5YBwPzGGny Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Tue, 2015-03-17 at 11:05 +0000, George Dunlap wrote: > On 03/17/2015 10:54 AM, Jan Beulich wrote: > > Finally, as said in different contexts earlier, I think unconditionally > > acquiring locks in dumping routines isn't the best practice. At least > > in non-debug builds I think these should be try-locks only, skipping > > the dumping when a lock is busy. >=20 > You mean so that we don't block the console if there turns out to be a > deadlock? >=20 > That makes some sense; but on a busy system that would mean a > non-negligible chance that any give keystroke would be missing > information about some cpu or other, which would be pretty frustrating > for someone trying to figure out the state of their system. >=20 Mmm... that's a very good point, actually, which I did not think about. > Would it make sense to have a version of spin_trylock for use in this > kind of situation that waits & retries a reasonable number of times > before giving up? >=20 Probably. After all, if one comes to the point of sending a debug-key, he most likely want to see the system status at (almost) any cost... Regards, Dario --=-TZmWlXqiM+5YBwPzGGny Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iEYEABECAAYFAlUIDaAACgkQk4XaBE3IOsT8dQCeOfeFxmFxL9pa2fK4uQ/q135S HuwAn0T70I1FHO33D98MwFiwjRwRREs+ =/pVW -----END PGP SIGNATURE----- --=-TZmWlXqiM+5YBwPzGGny-- --===============7006069983584452687== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel --===============7006069983584452687==--