On Wed, Jun 25, 2014 at 05:56:37PM +1000, Benjamin Herrenschmidt wrote: >On Wed, 2014-06-25 at 17:50 +1000, Alexey Kardashevskiy wrote: > >> > Yes, iommu_talbe's life time equals to PE lifetime, so when releasing a PE we >> > need to release the iommu table. Currently, there is one function to release >> > the iommu table, iommu_free_table() which takes a pointer of the iommu_table >> > and release it. >> > >> > If the iommu table in PE is just a part of PE, it will have some problem to >> > release it with iommu_free_table(). That's why I make it a pointer in PE >> > structure. >> >> So you are saying that you want to release PE by one kfree() and release >> iommu_table by another kfree (embedded into iommu_free_table()). For me >> that means that PE and iommu_table have different lifetime. >> >> And I cannot find the exact place in this patchset where you call >> iommu_free_table(), what do I miss? > >He has a point though... iommu_free_table() does a whole bunch of things >in addition to kfree at the end. > >This is a discrepancy in the iommu.c code, we don't allocate the table, >it's allocated by our callers, but we do free it in iommu_free_table(). > >My gut feeling is that we should fix that in the core by moving the >kfree() out of iommu_free_table() and back into vio.c and >pseries/iommu.c, the only two callers, otherwise we can't wrap the table >structure inside another object if we are going to ever free it. > Yes, this is another option. Move the kfree() outside could keep some logic in current code, like in pnv_pci_ioda_tce_invalidate(). We could get the tbl from a PE structure directly, instead of adding a field in tbl to point to the PE structure. >Cheers, >Ben. > > > -- Richard Yang Help you, Help me -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
