Messages in this thread | | | Subject | Re: [PATCH v5 02/12] iommu/vt-d: Manage scalalble mode PASID tables | From | Lu Baolu <> | Date | Thu, 6 Dec 2018 09:13:50 +0800 |
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Hi Joerg,
On 12/5/18 11:50 PM, Joerg Roedel wrote: > On Tue, Dec 04, 2018 at 01:58:06PM +0800, Lu Baolu wrote: >> This function is called in an unsleepable context. >> >> spin_lock(&lock) >> [...] >> if (pasid_table_is_necessary) >> allocate_pasid_table(dev) >> [...] >> spin_unlock(&lock) >> >> We can move it out of the lock range. >> >> How about >> >> if (pasid_table_is_necessary) >> pasid_table = allocate_pasid_table(dev) >> >> spin_lock(&lock) >> [...] >> if (pasid_table_is_necessary) >> set_up_pasid_table(pasid_table) >> [...] >> spin_unlock(&lock) > > Hmm, so when the IOMMU is configured in scalable mode we can just > allocate a pasid-table for the device when we set it up, right? > > Scalable mode is a boot-time decision, so we know for sure whether we > need a pasid-table on device-setup time. And the device-setup code it > preemptable, so I think it this allocation should be outside of any > spin-locked section.
Fair enough. I will fix this up in the next version.
Thank you for pointing this out.
Best regards, Lu Baolu
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