Re: [RFC]x86: clearing access bit don't flush tlb

2013-01-14 Thread Shaohua Li
On Tue, Jan 08, 2013 at 02:03:25AM -0500, Rik van Riel wrote: > On 01/08/2013 12:09 AM, H. Peter Anvin wrote: > >On 01/07/2013 09:08 PM, Rik van Riel wrote: > >>On 01/08/2013 12:03 AM, H. Peter Anvin wrote: > >>>On 01/07/2013 08:55 PM, Shaohua Li wrote: > > I searched a little bit, the

Re: [RFC]x86: clearing access bit don't flush tlb

2013-01-14 Thread Shaohua Li
On Tue, Jan 08, 2013 at 02:03:25AM -0500, Rik van Riel wrote: On 01/08/2013 12:09 AM, H. Peter Anvin wrote: On 01/07/2013 09:08 PM, Rik van Riel wrote: On 01/08/2013 12:03 AM, H. Peter Anvin wrote: On 01/07/2013 08:55 PM, Shaohua Li wrote: I searched a little bit, the change (doing TLB

Re: [RFC]x86: clearing access bit don't flush tlb

2013-01-07 Thread Rik van Riel
On 01/08/2013 12:09 AM, H. Peter Anvin wrote: On 01/07/2013 09:08 PM, Rik van Riel wrote: On 01/08/2013 12:03 AM, H. Peter Anvin wrote: On 01/07/2013 08:55 PM, Shaohua Li wrote: I searched a little bit, the change (doing TLB flush to clear access bit) is made between 2.6.7 - 2.6.8, I can't

Re: [RFC]x86: clearing access bit don't flush tlb

2013-01-07 Thread H. Peter Anvin
On 01/07/2013 09:08 PM, Rik van Riel wrote: > On 01/08/2013 12:03 AM, H. Peter Anvin wrote: >> On 01/07/2013 08:55 PM, Shaohua Li wrote: >>> >>> I searched a little bit, the change (doing TLB flush to clear access >>> bit) is >>> made between 2.6.7 - 2.6.8, I can't find the changelog, but I found

Re: [RFC]x86: clearing access bit don't flush tlb

2013-01-07 Thread Rik van Riel
On 01/08/2013 12:03 AM, H. Peter Anvin wrote: On 01/07/2013 08:55 PM, Shaohua Li wrote: I searched a little bit, the change (doing TLB flush to clear access bit) is made between 2.6.7 - 2.6.8, I can't find the changelog, but I found a patch:

Re: [RFC]x86: clearing access bit don't flush tlb

2013-01-07 Thread H. Peter Anvin
On 01/07/2013 08:55 PM, Shaohua Li wrote: > > I searched a little bit, the change (doing TLB flush to clear access bit) is > made between 2.6.7 - 2.6.8, I can't find the changelog, but I found a patch: >

Re: [RFC]x86: clearing access bit don't flush tlb

2013-01-07 Thread Shaohua Li
On Mon, Jan 07, 2013 at 02:31:21PM -0800, H. Peter Anvin wrote: > On 01/07/2013 07:14 AM, Rik van Riel wrote: > > On 01/07/2013 03:12 AM, Shaohua Li wrote: > >> > >> We use access bit to age a page at page reclaim. When clearing pte > >> access bit, > >> we could skip tlb flush for the virtual

Re: [RFC]x86: clearing access bit don't flush tlb

2013-01-07 Thread Simon Jeons
Hi Shaohua, On Mon, 2013-01-07 at 16:12 +0800, Shaohua Li wrote: > We use access bit to age a page at page reclaim. When clearing pte access bit, Who sets this flag to pte? mmu? tlb? > we could skip tlb flush for the virtual address. The side effect is if the pte > is in tlb and pte access bit

Re: [RFC]x86: clearing access bit don't flush tlb

2013-01-07 Thread H. Peter Anvin
On 01/07/2013 07:14 AM, Rik van Riel wrote: > On 01/07/2013 03:12 AM, Shaohua Li wrote: >> >> We use access bit to age a page at page reclaim. When clearing pte >> access bit, >> we could skip tlb flush for the virtual address. The side effect is if >> the pte >> is in tlb and pte access bit is

Re: [RFC]x86: clearing access bit don't flush tlb

2013-01-07 Thread Rik van Riel
On 01/07/2013 03:12 AM, Shaohua Li wrote: We use access bit to age a page at page reclaim. When clearing pte access bit, we could skip tlb flush for the virtual address. The side effect is if the pte is in tlb and pte access bit is unset, when cpu access the page again, cpu will not set pte's

[RFC]x86: clearing access bit don't flush tlb

2013-01-07 Thread Shaohua Li
We use access bit to age a page at page reclaim. When clearing pte access bit, we could skip tlb flush for the virtual address. The side effect is if the pte is in tlb and pte access bit is unset, when cpu access the page again, cpu will not set pte's access bit. So next time page reclaim can

[RFC]x86: clearing access bit don't flush tlb

2013-01-07 Thread Shaohua Li
We use access bit to age a page at page reclaim. When clearing pte access bit, we could skip tlb flush for the virtual address. The side effect is if the pte is in tlb and pte access bit is unset, when cpu access the page again, cpu will not set pte's access bit. So next time page reclaim can

Re: [RFC]x86: clearing access bit don't flush tlb

2013-01-07 Thread Rik van Riel
On 01/07/2013 03:12 AM, Shaohua Li wrote: We use access bit to age a page at page reclaim. When clearing pte access bit, we could skip tlb flush for the virtual address. The side effect is if the pte is in tlb and pte access bit is unset, when cpu access the page again, cpu will not set pte's

Re: [RFC]x86: clearing access bit don't flush tlb

2013-01-07 Thread H. Peter Anvin
On 01/07/2013 07:14 AM, Rik van Riel wrote: On 01/07/2013 03:12 AM, Shaohua Li wrote: We use access bit to age a page at page reclaim. When clearing pte access bit, we could skip tlb flush for the virtual address. The side effect is if the pte is in tlb and pte access bit is unset, when cpu

Re: [RFC]x86: clearing access bit don't flush tlb

2013-01-07 Thread Simon Jeons
Hi Shaohua, On Mon, 2013-01-07 at 16:12 +0800, Shaohua Li wrote: We use access bit to age a page at page reclaim. When clearing pte access bit, Who sets this flag to pte? mmu? tlb? we could skip tlb flush for the virtual address. The side effect is if the pte is in tlb and pte access bit is

Re: [RFC]x86: clearing access bit don't flush tlb

2013-01-07 Thread Shaohua Li
On Mon, Jan 07, 2013 at 02:31:21PM -0800, H. Peter Anvin wrote: On 01/07/2013 07:14 AM, Rik van Riel wrote: On 01/07/2013 03:12 AM, Shaohua Li wrote: We use access bit to age a page at page reclaim. When clearing pte access bit, we could skip tlb flush for the virtual address. The side

Re: [RFC]x86: clearing access bit don't flush tlb

2013-01-07 Thread H. Peter Anvin
On 01/07/2013 08:55 PM, Shaohua Li wrote: I searched a little bit, the change (doing TLB flush to clear access bit) is made between 2.6.7 - 2.6.8, I can't find the changelog, but I found a patch:

Re: [RFC]x86: clearing access bit don't flush tlb

2013-01-07 Thread Rik van Riel
On 01/08/2013 12:03 AM, H. Peter Anvin wrote: On 01/07/2013 08:55 PM, Shaohua Li wrote: I searched a little bit, the change (doing TLB flush to clear access bit) is made between 2.6.7 - 2.6.8, I can't find the changelog, but I found a patch:

Re: [RFC]x86: clearing access bit don't flush tlb

2013-01-07 Thread H. Peter Anvin
On 01/07/2013 09:08 PM, Rik van Riel wrote: On 01/08/2013 12:03 AM, H. Peter Anvin wrote: On 01/07/2013 08:55 PM, Shaohua Li wrote: I searched a little bit, the change (doing TLB flush to clear access bit) is made between 2.6.7 - 2.6.8, I can't find the changelog, but I found a patch:

Re: [RFC]x86: clearing access bit don't flush tlb

2013-01-07 Thread Rik van Riel
On 01/08/2013 12:09 AM, H. Peter Anvin wrote: On 01/07/2013 09:08 PM, Rik van Riel wrote: On 01/08/2013 12:03 AM, H. Peter Anvin wrote: On 01/07/2013 08:55 PM, Shaohua Li wrote: I searched a little bit, the change (doing TLB flush to clear access bit) is made between 2.6.7 - 2.6.8, I can't