From: Nadav Amit <namit@vmware.com>
To: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"aarcange@redhat.com" <aarcange@redhat.com>,
"luto@kernel.org" <luto@kernel.org>,
"torvalds@linux-foundation.org" <torvalds@linux-foundation.org>,
"keescook@google.com" <keescook@google.com>,
"hughd@google.com" <hughd@google.com>,
"jgross@suse.com" <jgross@suse.com>,
"x86@kernel.org" <x86@kernel.org>
Subject: Re: [PATCH 09/11] x86/pti: enable global pages for shared areas
Date: Fri, 23 Mar 2018 19:12:50 +0000 [thread overview]
Message-ID: <7B08037D-1682-406D-90F1-C2B5B1899F7F@vmware.com> (raw)
In-Reply-To: <20180323174500.64BD3D36@viggo.jf.intel.com>
Dave Hansen <dave.hansen@linux.intel.com> wrote:
>
> From: Dave Hansen <dave.hansen@linux.intel.com>
>
> The entry/exit text and cpu_entry_area are mapped into userspace and
> the kernel. But, they are not _PAGE_GLOBAL. This creates unnecessary
> TLB misses.
>
> Add the _PAGE_GLOBAL flag for these areas.
>
> static void __init
> diff -puN arch/x86/mm/pti.c~kpti-why-no-global arch/x86/mm/pti.c
> --- a/arch/x86/mm/pti.c~kpti-why-no-global 2018-03-21 16:32:00.799192311 -0700
> +++ b/arch/x86/mm/pti.c 2018-03-21 16:32:00.803192311 -0700
> @@ -300,6 +300,13 @@ pti_clone_pmds(unsigned long start, unsi
> return;
>
> /*
> + * Setting 'target_pmd' below creates a mapping in both
> + * the user and kernel page tables. It is effectively
> + * global, so set it as global in both copies.
> + */
> + *pmd = pmd_set_flags(*pmd, _PAGE_GLOBAL);
if (boot_cpu_has(X86_FEATURE_PGE)) ?
next prev parent reply other threads:[~2018-03-23 19:12 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-23 17:44 [PATCH 00/11] Use global pages with PTI Dave Hansen
2018-03-23 17:44 ` [PATCH 01/11] x86/mm: factor out pageattr _PAGE_GLOBAL setting Dave Hansen
2018-03-23 17:44 ` [PATCH 02/11] x86/mm: undo double _PAGE_PSE clearing Dave Hansen
2018-03-23 17:44 ` [PATCH 03/11] x86/mm: introduce "default" kernel PTE mask Dave Hansen
2018-03-23 17:44 ` [PATCH 04/11] x86/espfix: document use of _PAGE_GLOBAL Dave Hansen
2018-03-23 17:44 ` [PATCH 05/11] x86/mm: do not auto-massage page protections Dave Hansen
2018-03-23 19:15 ` Nadav Amit
2018-03-23 19:26 ` Dave Hansen
2018-03-23 19:34 ` Nadav Amit
2018-03-23 19:38 ` Dave Hansen
2018-03-24 15:10 ` kbuild test robot
2018-03-24 15:21 ` kbuild test robot
2018-03-23 17:44 ` [PATCH 06/11] x86/mm: remove extra filtering in pageattr code Dave Hansen
2018-03-23 17:44 ` [PATCH 07/11] x86/mm: comment _PAGE_GLOBAL mystery Dave Hansen
2018-03-23 17:44 ` [PATCH 08/11] x86/mm: do not forbid _PAGE_RW before init for __ro_after_init Dave Hansen
2018-03-23 17:45 ` [PATCH 09/11] x86/pti: enable global pages for shared areas Dave Hansen
2018-03-23 19:12 ` Nadav Amit [this message]
2018-03-23 19:36 ` Dave Hansen
2018-03-23 17:45 ` [PATCH 10/11] x86/pti: clear _PAGE_GLOBAL for kernel image Dave Hansen
2018-03-23 17:45 ` [PATCH 11/11] x86/pti: leave kernel text global for !PCID Dave Hansen
2018-03-23 18:26 ` [PATCH 00/11] Use global pages with PTI Linus Torvalds
2018-03-24 0:40 ` Dave Hansen
2018-03-24 0:46 ` Linus Torvalds
2018-03-24 0:54 ` Linus Torvalds
2018-03-24 11:05 ` Ingo Molnar
2018-03-27 13:36 ` Thomas Gleixner
2018-03-27 16:32 ` Dave Hansen
2018-03-27 17:51 ` Thomas Gleixner
2018-03-27 20:07 ` Ingo Molnar
2018-03-27 20:19 ` Dave Hansen
2018-03-29 0:17 ` Dave Hansen
2018-03-30 12:09 ` Ingo Molnar
2018-03-30 12:17 ` Ingo Molnar
2018-03-30 20:26 ` Dave Hansen
2018-03-30 20:32 ` Thomas Gleixner
2018-03-30 21:40 ` Dave Hansen
2018-03-31 5:39 ` Ingo Molnar
2018-03-31 18:19 ` Dave Hansen
2018-04-02 17:27 [PATCH 00/11] [v3] " Dave Hansen
2018-04-02 17:27 ` [PATCH 09/11] x86/pti: enable global pages for shared areas Dave Hansen
2018-04-02 17:56 ` Linus Torvalds
2018-04-02 20:41 ` Dave Hansen
2018-04-04 1:09 [PATCH 00/11] [v4] Use global pages with PTI Dave Hansen
2018-04-04 1:10 ` [PATCH 09/11] x86/pti: enable global pages for shared areas Dave Hansen
2018-04-04 4:45 ` Nadav Amit
2018-04-04 15:52 ` Dave Hansen
2018-04-04 16:09 ` Nadav Amit
2018-04-04 18:14 ` Thomas Gleixner
2018-04-06 20:55 [PATCH 00/11] [v5] Use global pages with PTI Dave Hansen
2018-04-06 20:55 ` [PATCH 09/11] x86/pti: enable global pages for shared areas Dave Hansen
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