From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vitaly Kuznetsov Subject: Re: [PATCH v8 05/11] xen: grant_table: implement grant_table_warn_active_grants() Date: Mon, 13 Jul 2015 15:44:04 +0200 Message-ID: <87egkcyxy3.fsf@vitty.brq.redhat.com> References: <1435075913-335-1-git-send-email-vkuznets@redhat.com> <1435075913-335-6-git-send-email-vkuznets@redhat.com> <20150710162425.GB24518@l.oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta5.messagelabs.com ([195.245.231.135]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1ZEe1n-0005p8-JK for xen-devel@lists.xenproject.org; Mon, 13 Jul 2015 13:44:15 +0000 In-Reply-To: <20150710162425.GB24518@l.oracle.com> (Konrad Rzeszutek Wilk's message of "Fri, 10 Jul 2015 12:24:25 -0400") List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Konrad Rzeszutek Wilk Cc: Wei Liu , Andrew Jones , Keir Fraser , Ian Campbell , Stefano Stabellini , Andrew Cooper , Julien Grall , Ian Jackson , Olaf Hering , Tim Deegan , David Vrabel , Jan Beulich , xen-devel@lists.xenproject.org, Daniel De Graaf List-Id: xen-devel@lists.xenproject.org Konrad Rzeszutek Wilk writes: > On Tue, Jun 23, 2015 at 06:11:47PM +0200, Vitaly Kuznetsov wrote: >> Log first 10 active grants of a domain. This function is going to be used >> for soft reset, active grants on this path usually mean misbehaving backends >> refusing to release their mappings on shutdown. > > Is there an particular reason 10 was choosen instead of 42 for example :-) > I was inpired by dump_pageframe_info() :-) > Also the 10 should probably have an #define for it. > Ok, any preferred place/name for such define? > Not sure I understand the usage case - except for development uses > to report on the Xen console? But if that is the case why not > use the 'g' on the ring console? If there is a misbehaving backend and this cases the domain to crash right after the soft reset 'g' option will not be available and it won't be clear what caused the domain to crash. > >> >> Signed-off-by: Vitaly Kuznetsov >> --- >> xen/common/grant_table.c | 31 +++++++++++++++++++++++++++++++ >> xen/include/xen/grant_table.h | 5 +++++ >> 2 files changed, 36 insertions(+) >> >> diff --git a/xen/common/grant_table.c b/xen/common/grant_table.c >> index db5e5db..c67db28 100644 >> --- a/xen/common/grant_table.c >> +++ b/xen/common/grant_table.c >> @@ -3309,6 +3309,37 @@ gnttab_release_mappings( >> } >> } >> >> +void grant_table_warn_active_grants(struct domain *d) >> +{ >> + struct grant_table *gt = d->grant_table; >> + struct active_grant_entry *act; >> + grant_ref_t ref; >> + unsigned int nr_active = 0; >> + >> + read_lock(>->lock); >> + >> + for ( ref = 0; ref != nr_grant_entries(gt); ref++ ) >> + { >> + act = active_entry_acquire(gt, ref); >> + if ( !act->pin ) >> + { >> + active_entry_release(act); >> + continue; >> + } >> + >> + nr_active++; >> + if ( nr_active <= 10 ) >> + printk(XENLOG_G_DEBUG "Dom%d has an active grant: GFN: %lx" >> + " (MFN: %lx)\n", d->domain_id, act->gfn, act->frame); >> + active_entry_release(act); >> + } >> + >> + if ( nr_active > 10 ) >> + printk(XENLOG_G_DEBUG "Dom%d has too many (%d) active grants" >> + " to report\n", d->domain_id, nr_active); >> + >> + read_unlock(>->lock); >> +} >> >> void >> grant_table_destroy( >> diff --git a/xen/include/xen/grant_table.h b/xen/include/xen/grant_table.h >> index 9c7b5a3..54005cc 100644 >> --- a/xen/include/xen/grant_table.h >> +++ b/xen/include/xen/grant_table.h >> @@ -90,6 +90,11 @@ void grant_table_destroy( >> struct domain *d); >> void grant_table_init_vcpu(struct vcpu *v); >> >> +/* >> + * Check if domain has active grants and log first 10 of them. >> + */ >> +void grant_table_warn_active_grants(struct domain *d); >> + >> /* Domain death release of granted mappings of other domains' memory. */ >> void >> gnttab_release_mappings( >> -- >> 2.4.2 >> -- Vitaly