On Wed, Jul 12, 2023 at 05:18:00PM +0200, Alexandre Ghiti wrote: > On 12/07/2023 09:08, Conor Dooley wrote: > > On Tue, Jul 11, 2023 at 09:54:30AM +0200, Alexandre Ghiti wrote: > > > This series optimizes the tlb flushes on riscv which used to simply > > > flush the whole tlb whatever the size of the range to flush or the size > > > of the stride. > > > > > > Patch 3 introduces a threshold that is microarchitecture specific and > > > will very likely be modified by vendors, not sure though which mechanism > > > we'll use to do that (dt? alternatives? vendor initialization code?). > > > @Conor any idea how to achieve this? It's in my queue of things to look at, just been prioritising the extension related stuff the last few days. Hopefully I'll have a chance to think about this tomorrow.. Famous last words probably. > > > Next steps would be to implement: > > > - svinval extension as Mayuresh did here [1] > > > - BATCHED_UNMAP_TLB_FLUSH (I'll wait for arm64 patchset to land) > > > - MMU_GATHER_RCU_TABLE_FREE > > > - MMU_GATHER_MERGE_VMAS > > > > > > Any other idea welcome. > > > > > > [1] https://lore.kernel.org/linux-riscv/20230623123849.1425805-1-mchitale@xxxxxxxxxxxxxxxx/ > > > > > > Alexandre Ghiti (4): > > > riscv: Improve flush_tlb() > > > riscv: Improve flush_tlb_range() for hugetlb pages > > > riscv: Make __flush_tlb_range() loop over pte instead of flushing the > > > whole tlb > > The whole series does not build on nommu & this one adds a build warning > > for regular builds: > > + 1 ../arch/riscv/mm/tlbflush.c:32:15: warning: symbol 'tlb_flush_all_threshold' was not declared. Should it be static? > > > > Cheers, > > Conor. > > > I'll fix the nommu build, sorry about that. Weird I missed this warning, > that's an LLVM build right? That variable will need to overwritten by the > vendors, so that should not be static (but it will depend on what solution > we implement). Just make it static until we actually have a vendor implementation of this stuff please, since we don't know what that will look like yet.
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