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authorMatthew Wilcox (Oracle) <willy@infradead.org>2023-08-02 18:13:29 +0300
committerAndrew Morton <akpm@linux-foundation.org>2023-08-25 02:20:18 +0300
commitf9bff0e31881d03badf191d3b0005839391f5f2b (patch)
tree6c7204be6cfe843fcdf3ad34bf4ae35dfa3d7c39 /lib
parentf82e6bf9bb9b6e1dc001320a88eee67d7ac31e96 (diff)
downloadlinux-f9bff0e31881d03badf191d3b0005839391f5f2b.tar.xz
minmax: add in_range() macro
Patch series "New page table range API", v6. This patchset changes the API used by the MM to set up page table entries. The four APIs are: set_ptes(mm, addr, ptep, pte, nr) update_mmu_cache_range(vma, addr, ptep, nr) flush_dcache_folio(folio) flush_icache_pages(vma, page, nr) flush_dcache_folio() isn't technically new, but no architecture implemented it, so I've done that for them. The old APIs remain around but are mostly implemented by calling the new interfaces. The new APIs are based around setting up N page table entries at once. The N entries belong to the same PMD, the same folio and the same VMA, so ptep++ is a legitimate operation, and locking is taken care of for you. Some architectures can do a better job of it than just a loop, but I have hesitated to make too deep a change to architectures I don't understand well. One thing I have changed in every architecture is that PG_arch_1 is now a per-folio bit instead of a per-page bit when used for dcache clean/dirty tracking. This was something that would have to happen eventually, and it makes sense to do it now rather than iterate over every page involved in a cache flush and figure out if it needs to happen. The point of all this is better performance, and Fengwei Yin has measured improvement on x86. I suspect you'll see improvement on your architecture too. Try the new will-it-scale test mentioned here: https://lore.kernel.org/linux-mm/20230206140639.538867-5-fengwei.yin@intel.com/ You'll need to run it on an XFS filesystem and have CONFIG_TRANSPARENT_HUGEPAGE set. This patchset is the basis for much of the anonymous large folio work being done by Ryan, so it's received quite a lot of testing over the last few months. This patch (of 38): Determine if a value lies within a range more efficiently (subtraction + comparison vs two comparisons and an AND). It also has useful (under some circumstances) behaviour if the range exceeds the maximum value of the type. Convert all the conflicting definitions of in_range() within the kernel; some can use the generic definition while others need their own definition. Link: https://lkml.kernel.org/r/20230802151406.3735276-1-willy@infradead.org Link: https://lkml.kernel.org/r/20230802151406.3735276-2-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'lib')
-rw-r--r--lib/logic_pio.c3
1 files changed, 0 insertions, 3 deletions
diff --git a/lib/logic_pio.c b/lib/logic_pio.c
index 07b4b9a1f54b..2ea564a40064 100644
--- a/lib/logic_pio.c
+++ b/lib/logic_pio.c
@@ -20,9 +20,6 @@
static LIST_HEAD(io_range_list);
static DEFINE_MUTEX(io_range_mutex);
-/* Consider a kernel general helper for this */
-#define in_range(b, first, len) ((b) >= (first) && (b) < (first) + (len))
-
/**
* logic_pio_register_range - register logical PIO range for a host
* @new_range: pointer to the IO range to be registered.