From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Borkmann Subject: Re: [suspend/resume] Re: userspace notification from module Date: Mon, 04 Jan 2010 13:46:16 +0100 Message-ID: <4B41E318.4050809__2356.9353660152$1262619355$gmane$org@gmail.com> References: <686edb2c.6263643a.4b3f4a3b.b60b3@o2.pl> <201001040030.01256.rjw@sisk.pl> <54ac764e.502c1a33.4b4129c3.9dc1b@o2.pl> <201001040045.39517.rjw@sisk.pl> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============6787042852405135384==" Return-path: In-Reply-To: <201001040045.39517.rjw@sisk.pl> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Mime-version: 1.0 Sender: linux-pm-bounces@lists.linux-foundation.org Errors-To: linux-pm-bounces@lists.linux-foundation.org To: "Rafael J. Wysocki" Cc: awalls@radix.net, linux-kernel@vger.kernel.org, =?UTF-8?B?QmFydMWCb21pZWogWmltb8WE?= , linux-pm@lists.linux-foundation.org, danborkmann@googlemail.com List-Id: linux-pm@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --===============6787042852405135384== Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig617ACEB1397EFE08C9EE3CDF" This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig617ACEB1397EFE08C9EE3CDF Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Rafael J. Wysocki wrote: > On Monday 04 January 2010, Bart=C5=82omiej Zimo=C5=84 wrote: >> And what do You think about sending extra signals to processes? >=20 > I don't see a problem with this in principle, although I don't think si= gnals > are very suitable for this particular purpose, because you need two-way= > communication between the power manager and the processes it's going to= > notify (because it has to wait for the processes to finish their prepar= ations > and to tell it that they are ready). Again, just to abandon some thoughts... do you really need that "two-way communication"? I mean if the kernel delivers that specific signal to the process/task_struct [do_signal():handle_signal()] it has to save the original execution context that will later on be restored after the non-default signal handling function returns. This is our ACK / notification for the successful return of the programs "suspend handler". The kernel module (if such exists) could be notified about that for instance by a simple notifier hook within kernelspace. I mean if I see this right, the "two-way" is just for the ACK isn't it? Best regards, Daniel --------------enig617ACEB1397EFE08C9EE3CDF Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAktB4xgACgkQ5AxJm1m3CC9vxQCfWdKkD2G/vFXqz3D3R3U0nsgD PasAn2JqmawTG+k8NBjbddSFCxOggi+B =8/RW -----END PGP SIGNATURE----- --------------enig617ACEB1397EFE08C9EE3CDF-- --===============6787042852405135384== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline --===============6787042852405135384==--