From: "Jan Beulich" <JBeulich@suse.com>
To: Quan Xu <quan.xu@intel.com>
Cc: Kevin Tian <kevin.tian@intel.com>, Feng Wu <feng.wu@intel.com>,
Andrew Cooper <andrew.cooper3@citrix.com>,
Dario Faggioli <dario.faggioli@citrix.com>,
xen-devel@lists.xen.org,
Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>,
Keir Fraser <keir@xen.org>
Subject: Re: [PATCH v3 2/2] IOMMU/spinlock: Make the pcidevs_lock a recursive one
Date: Thu, 10 Mar 2016 02:52:48 -0700 [thread overview]
Message-ID: <56E1520002000078000DB243@prv-mh.provo.novell.com> (raw)
In-Reply-To: <1457529455-38314-3-git-send-email-quan.xu@intel.com>
>>> On 09.03.16 at 14:17, <quan.xu@intel.com> wrote:
> Signed-off-by: Quan Xu <quan.xu@intel.com>
> Acked-by: Kevin Tian <kevin.tian@intel.com>
The patch itself looks mostly fine now (see below for the minor left
issues), but the complete lack of a description (which should state
why this change is being done) makes this not ready to go in
anyway.
> --- a/xen/drivers/passthrough/pci.c
> +++ b/xen/drivers/passthrough/pci.c
> @@ -48,7 +48,7 @@ struct pci_seg {
> } bus2bridge[MAX_BUSES];
> };
>
> -spinlock_t pcidevs_lock = SPIN_LOCK_UNLOCKED;
> +static spinlock_t _pcidevs_lock = SPIN_LOCK_UNLOCKED;
Why the renaming?
> @@ -103,6 +103,26 @@ static int pci_segments_iterate(
> return rc;
> }
>
> +void pcidevs_lock(void)
> +{
> + spin_lock_recursive(&_pcidevs_lock);
> +}
> +
> +void pcidevs_unlock(void)
> +{
> + spin_unlock_recursive(&_pcidevs_lock);
> +}
> +
> +int pcidevs_is_locked(void)
bool_t
> +{
> + return spin_is_locked(&_pcidevs_lock);
> +}
> +
> +int pcidevs_trylock(void)
bool_t
(To avoid another round, please be aware that the underlying
spin lock primitives still [wrongly] use "int", so to be fully correct
you will need to use !! in both return statements, unless you
feel like (in another prereq patch) to adjust those primitives too.
> +{
> + return spin_trylock_recursive(&_pcidevs_lock);
> +}
I also think that it would be a good idea to place these helpers
and the lock definition next to each other.
Jan
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next prev parent reply other threads:[~2016-03-10 9:52 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-09 13:17 [PATCH v3 0/2] Make the pcidevs_lock a recursive one Quan Xu
2016-03-09 13:17 ` [PATCH v3 1/2] IOMMU/spinlock: Fix a bug found in AMD IOMMU initialization Quan Xu
2016-03-09 14:59 ` Dario Faggioli
2016-03-10 6:12 ` Xu, Quan
2016-03-11 3:24 ` Meng Xu
2016-03-11 6:54 ` Xu, Quan
2016-03-11 10:35 ` Dario Faggioli
2016-03-11 12:36 ` Xu, Quan
2016-03-11 13:58 ` Dario Faggioli
2016-03-11 14:49 ` Meng Xu
2016-03-11 15:55 ` Dario Faggioli
2016-03-11 17:17 ` Meng Xu
2016-03-11 14:41 ` Meng Xu
2016-03-11 16:12 ` Dario Faggioli
2016-03-09 13:17 ` [PATCH v3 2/2] IOMMU/spinlock: Make the pcidevs_lock a recursive one Quan Xu
2016-03-09 17:45 ` Dario Faggioli
2016-03-10 1:21 ` Xu, Quan
2016-03-10 9:52 ` Jan Beulich [this message]
2016-03-10 11:27 ` Xu, Quan
2016-03-10 13:06 ` Jan Beulich
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