[PATCH] MIPS: Flush huge TLB

[PATCH] MIPS: Flush huge TLB

[Hillf Danton]

When flushing TLB, if @vma is backed by huge page, we could flush huge TLB,
due to that huge page is defined to be far from normal page.

Signed-off-by: Hillf Danton <dhillf@gmail.com>
---

--- a/arch/mips/mm/tlb-r4k.c	Mon May 30 21:17:04 2011
+++ b/arch/mips/mm/tlb-r4k.c	Fri Nov 18 21:13:13 2011
@@ -120,22 +120,30 @@ void local_flush_tlb_range(struct vm_are

 	if (cpu_context(cpu, mm) != 0) {
 		unsigned long size, flags;
+		int huge = is_vm_hugetlb_page(vma);

 		ENTER_CRITICAL(flags);
-		size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
-		size = (size + 1) >> 1;
+		if (huge) {
+			start = round_down(start, HPAGE_SIZE);
+			end = round_up(end, HPAGE_SIZE);
+			size = (end - start) >> HPAGE_SHIFT;
+		} else {
+			start = round_down(start, PAGE_SIZE << 1);
+			end = round_up(end, PAGE_SIZE << 1);
+			size = (end - start) >> (PAGE_SHIFT + 1);
+		}
 		if (size <= current_cpu_data.tlbsize/2) {
 			int oldpid = read_c0_entryhi();
 			int newpid = cpu_asid(cpu, mm);

-			start &= (PAGE_MASK << 1);
-			end += ((PAGE_SIZE << 1) - 1);
-			end &= (PAGE_MASK << 1);
 			while (start < end) {
 				int idx;

 				write_c0_entryhi(start | newpid);
-				start += (PAGE_SIZE << 1);
+				if (huge)
+					start += HPAGE_SIZE;
+				else
+					start += (PAGE_SIZE << 1);
 				mtc0_tlbw_hazard();
 				tlb_probe();
 				tlb_probe_hazard();

Re: [PATCH] MIPS: Flush huge TLB

[Ralf Baechle]

On Fri, Nov 18, 2011 at 09:15:39PM +0800, Hillf Danton wrote:

> When flushing TLB, if @vma is backed by huge page, we could flush huge TLB,
> due to that huge page is defined to be far from normal page.
> 
> Signed-off-by: Hillf Danton <dhillf@gmail.com>

It seems this patch is identical to
https://patchwork.linux-mips.org/patch/2825/ which I've already applied?

  Ralf

Re: [PATCH] MIPS: Flush huge TLB

[Hillf Danton]

On Fri, Nov 18, 2011 at 10:46 PM, Ralf Baechle <ralf@linux-mips.org> wrote:
> On Fri, Nov 18, 2011 at 09:15:39PM +0800, Hillf Danton wrote:
>
>> When flushing TLB, if @vma is backed by huge page, we could flush huge TLB,
>> due to that huge page is defined to be far from normal page.
>>
>> Signed-off-by: Hillf Danton <dhillf@gmail.com>
>
> It seems this patch is identical to
> https://patchwork.linux-mips.org/patch/2825/ which I've already applied?
>

Maybe you forget the following message:)

btw, I want to change
+			size = (end - start) >> HPAGE_SHIFT;
to
+			size = (end - start) / HPAGE_SIZE;

if it is not too late.

Best regards
Hillf

On Wed, Nov 16, 2011 at 10:52 PM, Ralf Baechle <ralf@linux-mips.org> wrote:
> On Fri, Oct 14, 2011 at 09:09:37PM +0800, Hillf Danton wrote:
>
>> Subject: Flush huge TLB
>> From: Hillf Danton <dhillf@gmail.com>
>>
>> When flushing TLB, if @vma is backed by huge page, we could flush huge TLB,
>> due to that huge page is defined to be far from normal page.
>>
>> Signed-off-by: Hillf Danton <dhillf@gmail.com>
>> Acked-by: David Daney <david.daney@cavium.com>
>
> I assume this 2nd version was actually meant to be applied, not just for RFC
> so I've queued it for 3.3.  But you better remove that RFC from subject and
> start a fresh mail thread when posting a patch to avoid confusion!
>
> Thanks,
>
>  Ralf
>

Re: [PATCH] MIPS: Flush huge TLB

[Sergei Shtylyov]

Hello.

On 18-11-2011 17:15, Hillf Danton wrote:

> When flushing TLB, if @vma is backed by huge page, we could flush huge TLB,
> due to that huge page is defined to be far from normal page.

> Signed-off-by: Hillf Danton<dhillf@gmail.com>
> ---

> --- a/arch/mips/mm/tlb-r4k.c	Mon May 30 21:17:04 2011
> +++ b/arch/mips/mm/tlb-r4k.c	Fri Nov 18 21:13:13 2011
> @@ -120,22 +120,30 @@ void local_flush_tlb_range(struct vm_are
[...]
>   				write_c0_entryhi(start | newpid);
> -				start += (PAGE_SIZE<<  1);
> +				if (huge)
> +					start += HPAGE_SIZE;
> +				else
> +					start += (PAGE_SIZE << 1);

    Parens not needed.

WBR, Sergei