Messages in this thread | ![/](/images/icornerl.gif) | | Date | Wed, 31 Jan 2024 09:58:21 -0500 | Subject | Re: [RFC PATCH v2 7/8] Introduce dcache_is_aliasing() across all architectures | From | Mathieu Desnoyers <> |
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On 2024-01-30 21:48, Dave Chinner wrote: > On Tue, Jan 30, 2024 at 11:52:54AM -0500, Mathieu Desnoyers wrote: >> Introduce a generic way to query whether the dcache is virtually aliased >> on all architectures. Its purpose is to ensure that subsystems which >> are incompatible with virtually aliased data caches (e.g. FS_DAX) can >> reliably query this. >> >> For dcache aliasing, there are three scenarios dependending on the >> architecture. Here is a breakdown based on my understanding: >> >> A) The dcache is always aliasing: >> >> * arc >> * csky >> * m68k (note: shared memory mappings are incoherent ? SHMLBA is missing there.) >> * sh >> * parisc > > /me wonders why the dentry cache aliasing has problems on these > systems. > > Oh, dcache != fs/dcache.c (the VFS dentry cache). > > Can you please rename this function appropriately so us dumb > filesystem people don't confuse cpu data cache configurations with > the VFS dentry cache aliasing when we read this code? Something like > cpu_dcache_is_aliased(), perhaps?
Good point, will do. I'm planning go rename as follows for v3 to eliminate confusion with dentry cache (and with "page cache" in general):
ARCH_HAS_CACHE_ALIASING -> ARCH_HAS_CPU_CACHE_ALIASING dcache_is_aliasing() -> cpu_dcache_is_aliasing()
I noticed that you suggested "aliased" rather than "aliasing", but I followed what arm64 did for icache_is_aliasing(). Do you have a strong preference one way or another ?
Thanks,
Mathieu
-- Mathieu Desnoyers EfficiOS Inc. https://www.efficios.com
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