linux-kernel - [PATCH v2 10/11] x86/mm: Be more consistent wrt PAGE_SHIFT vs PAGE

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Date:   Mon, 22 May 2017 15:30:10 -0700
From:   Andy Lutomirski <luto@...nel.org>
To:     X86 ML <x86@...nel.org>
Cc:     "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Borislav Petkov <bpetkov@...e.de>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Mel Gorman <mgorman@...e.de>,
        "linux-mm@...ck.org" <linux-mm@...ck.org>,
        Nadav Amit <nadav.amit@...il.com>,
        Andy Lutomirski <luto@...nel.org>,
        Rik van Riel <riel@...hat.com>,
        Dave Hansen <dave.hansen@...el.com>,
        Nadav Amit <namit@...are.com>, Michal Hocko <mhocko@...e.com>,
        Arjan van de Ven <arjan@...ux.intel.com>
Subject: [PATCH v2 10/11] x86/mm: Be more consistent wrt PAGE_SHIFT vs PAGE_SIZE in tlb flush code

Nadav pointed out that some code used PAGE_SIZE and other code used
PAGE_SHIFT.  Use PAGE_SHIFT instead of multiplying or dividing by
PAGE_SIZE.

Requested-by: Nadav Amit <nadav.amit@...il.com>
Cc: Rik van Riel <riel@...hat.com>
Cc: Dave Hansen <dave.hansen@...el.com>
Cc: Nadav Amit <namit@...are.com>
Cc: Michal Hocko <mhocko@...e.com>
Cc: Arjan van de Ven <arjan@...ux.intel.com>
Cc: Andrew Morton <akpm@...ux-foundation.org>
Signed-off-by: Andy Lutomirski <luto@...nel.org>
---
 arch/x86/mm/tlb.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c
index 4bfadb869a1e..20659edd9347 100644
--- a/arch/x86/mm/tlb.c
+++ b/arch/x86/mm/tlb.c
@@ -220,8 +220,7 @@ static void flush_tlb_func_common(const struct flush_tlb_info *f,
 		trace_tlb_flush(reason, TLB_FLUSH_ALL);
 	} else {
 		unsigned long addr;
-		unsigned long nr_pages =
-			(f->end - f->start) / PAGE_SIZE;
+		unsigned long nr_pages = (f->end - f->start) >> PAGE_SHIFT;
 		addr = f->start;
 		while (addr < f->end) {
 			__flush_tlb_single(addr);
@@ -351,7 +350,7 @@ void flush_tlb_kernel_range(unsigned long start, unsigned long end)
 
 	/* Balance as user space task's flush, a bit conservative */
 	if (end == TLB_FLUSH_ALL ||
-	    (end - start) > tlb_single_page_flush_ceiling * PAGE_SIZE) {
+	    (end - start) > tlb_single_page_flush_ceiling >> PAGE_SHIFT) {
 		on_each_cpu(do_flush_tlb_all, NULL, 1);
 	} else {
 		struct flush_tlb_info info;
-- 
2.9.3