From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35448) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZXkMN-0002OJ-Vb for qemu-devel@nongnu.org; Fri, 04 Sep 2015 02:20:29 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZXkMK-0005n3-JG for qemu-devel@nongnu.org; Fri, 04 Sep 2015 02:20:27 -0400 Date: Fri, 4 Sep 2015 16:11:38 +1000 From: David Gibson Message-ID: <20150904061138.GY6537@voom.redhat.com> References: <1438838837-28504-1-git-send-email-bharata@linux.vnet.ibm.com> <1438838837-28504-5-git-send-email-bharata@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="sT0SRK93LqpGW452" Content-Disposition: inline In-Reply-To: <1438838837-28504-5-git-send-email-bharata@linux.vnet.ibm.com> Subject: Re: [Qemu-devel] [RFC PATCH v4 04/11] cpus: Add a sync version of cpu_remove() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Bharata B Rao Cc: mdroth@linux.vnet.ibm.com, aik@ozlabs.ru, agraf@suse.de, qemu-devel@nongnu.org, qemu-ppc@nongnu.org, tyreld@linux.vnet.ibm.com, nfont@linux.vnet.ibm.com, imammedo@redhat.com, afaerber@suse.de --sT0SRK93LqpGW452 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Aug 06, 2015 at 10:57:10AM +0530, Bharata B Rao wrote: > This sync API will be used by the CPU hotplug code to wait for the CPU to > completely get removed before flagging the failure to the device_add > command. >=20 > Sync version of this call is needed to correctly recover from CPU > realization failures when ->plug() handler fails. >=20 > Signed-off-by: Bharata B Rao > --- > cpus.c | 14 ++++++++++++++ > include/qom/cpu.h | 8 ++++++++ > 2 files changed, 22 insertions(+) >=20 > diff --git a/cpus.c b/cpus.c > index 73ae2e7..9d9644e 100644 > --- a/cpus.c > +++ b/cpus.c > @@ -999,6 +999,8 @@ static void *qemu_kvm_cpu_thread_fn(void *arg) > qemu_kvm_wait_io_event(cpu); > if (cpu->exit && !cpu_can_run(cpu)) { > qemu_kvm_destroy_vcpu(cpu); > + cpu->created =3D false; > + qemu_cond_signal(&qemu_cpu_cond); > qemu_mutex_unlock(&qemu_global_mutex); > return NULL; > } > @@ -1104,6 +1106,8 @@ static void *qemu_tcg_cpu_thread_fn(void *arg) > } > if (remove_cpu) { > qemu_tcg_destroy_vcpu(remove_cpu); > + cpu->created =3D false; > + qemu_cond_signal(&qemu_cpu_cond); > remove_cpu =3D NULL; > } > } > @@ -1283,6 +1287,16 @@ void cpu_remove(CPUState *cpu) > qemu_cpu_kick(cpu); > } > =20 > +void cpu_remove_sync(CPUState *cpu) > +{ > + cpu->stop =3D true; > + cpu->exit =3D true; > + qemu_cpu_kick(cpu); It would be nicer for this to call the async cpu_remove() above, to ensure they stay in sync. > + while (cpu->created) { > + qemu_cond_wait(&qemu_cpu_cond, &qemu_global_mutex); > + } > +} > + > /* For temporary buffers for forming a name */ > #define VCPU_THREAD_NAME_SIZE 16 > =20 > diff --git a/include/qom/cpu.h b/include/qom/cpu.h > index 136d9fe..65c6852 100644 > --- a/include/qom/cpu.h > +++ b/include/qom/cpu.h > @@ -655,6 +655,14 @@ void cpu_resume(CPUState *cpu); > */ > void cpu_remove(CPUState *cpu); > =20 > + /** > + * cpu_remove_sync: > + * @cpu: The CPU to remove. > + * > + * Requests the CPU to be removed and waits till it is removed. > + */ > +void cpu_remove_sync(CPUState *cpu); > + > /** > * qemu_init_vcpu: > * @cpu: The vCPU to initialize. --=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 --sT0SRK93LqpGW452 Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJV6TYZAAoJEGw4ysog2bOSD5MP/2/ndwxNtxylqF23osCtO4U6 a6WkZJOE/ant8cUPYUsVlHC8RY6qGp4db3MZ1yMSeZdxdG4qElzIxZmfKTsDE5m4 L/BJR9nQRymUa4iRddkkYCG0pjMIAPnCovGxjR5zDwBYthHhvJmD4LDDjG6WiiK+ QaDspcdvZk4tiGb4pWTUI5/DxuDWs51kdPbJH0hT9S5OZ36+hnyl4YMy2E4H7onS Yz7PDSuQfPJXINBa98KIH6QKBeHteqTf55WDP3/Ysdn9yT37jg8ULDM7fHvZldga 7ureYRE+xg+hbLZpcBckO++dNDXL/eCIKhAlfISmWbkU85cd2o1/KmR/jH9Te8Nq QEOFTykUlOyVzqwxHWF3Q6jeoKj3B/mKfC4nKaT2BjfkJC2LC//ww1cfSWuW7gni FiZ/jqa0kBBTszRvb3oD1vrVkyxD3OinM6hapd0Hj/LcK7lzaSkdn1UMH5alnz/B Jlbcptf1rIT1QCpoxKzoJx0GvE+Mc+Y1N1ydFl/WOXxIFtPspb16+7900gjroiWL I/kTndPNlbsDIB87nntaSO7fTZCNKw3ZShaSkHw1hbx749NkH32nZFUozQqTSUZX KAio9QQyFkV0Gs7krtJvojluYVYqGHx3m93qr6q7xL2wsGoZ/qv4j8rhcR4Epbe2 6IE34tl84jrDfal3Xlg0 =ZdwP -----END PGP SIGNATURE----- --sT0SRK93LqpGW452--