From: Andy Lutomirski <luto@kernel.org>
To: x86@kernel.org
Cc: linux-kernel@vger.kernel.org, Borislav Petkov <bp@alien8.de>,
Linus Torvalds <torvalds@linux-foundation.org>,
Andrew Morton <akpm@linux-foundation.org>,
Mel Gorman <mgorman@suse.de>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
Nadav Amit <nadav.amit@gmail.com>, Rik van Riel <riel@redhat.com>,
Dave Hansen <dave.hansen@intel.com>,
Arjan van de Ven <arjan@linux.intel.com>,
Peter Zijlstra <peterz@infradead.org>,
Andy Lutomirski <luto@kernel.org>
Subject: [PATCH v3 09/11] x86/mm: Add nopcid to turn off PCID
Date: Tue, 20 Jun 2017 22:22:15 -0700 [thread overview]
Message-ID: <17c3a4f2e16aa83cbfea8ca9957ce75efbcf7f95.1498022414.git.luto@kernel.org> (raw)
In-Reply-To: <cover.1498022414.git.luto@kernel.org>
In-Reply-To: <cover.1498022414.git.luto@kernel.org>
The parameter is only present on x86_64 systems to save a few bytes,
as PCID is always disabled on x86_32.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
---
Documentation/admin-guide/kernel-parameters.txt | 2 ++
arch/x86/kernel/cpu/common.c | 18 ++++++++++++++++++
2 files changed, 20 insertions(+)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 0f5c3b4347c6..aa385109ae58 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -2648,6 +2648,8 @@
nopat [X86] Disable PAT (page attribute table extension of
pagetables) support.
+ nopcid [X86-64] Disable the PCID cpu feature.
+
norandmaps Don't use address space randomization. Equivalent to
echo 0 > /proc/sys/kernel/randomize_va_space
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index c8b39870f33e..904485e7b230 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -168,6 +168,24 @@ static int __init x86_mpx_setup(char *s)
}
__setup("nompx", x86_mpx_setup);
+#ifdef CONFIG_X86_64
+static int __init x86_pcid_setup(char *s)
+{
+ /* require an exact match without trailing characters */
+ if (strlen(s))
+ return 0;
+
+ /* do not emit a message if the feature is not present */
+ if (!boot_cpu_has(X86_FEATURE_PCID))
+ return 1;
+
+ setup_clear_cpu_cap(X86_FEATURE_PCID);
+ pr_info("nopcid: PCID feature disabled\n");
+ return 1;
+}
+__setup("nopcid", x86_pcid_setup);
+#endif
+
static int __init x86_noinvpcid_setup(char *s)
{
/* noinvpcid doesn't accept parameters */
--
2.9.4
next prev parent reply other threads:[~2017-06-21 5:24 UTC|newest]
Thread overview: 78+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-21 5:22 [PATCH v3 00/11] PCID and improved laziness Andy Lutomirski
2017-06-21 5:22 ` [PATCH v3 01/11] x86/mm: Don't reenter flush_tlb_func_common() Andy Lutomirski
2017-06-21 8:01 ` Thomas Gleixner
2017-06-21 8:49 ` Borislav Petkov
2017-06-21 15:15 ` Andy Lutomirski
2017-06-21 23:26 ` Nadav Amit
2017-06-22 2:27 ` Andy Lutomirski
2017-06-22 7:32 ` Ingo Molnar
2017-06-21 5:22 ` [PATCH v3 02/11] x86/ldt: Simplify LDT switching logic Andy Lutomirski
2017-06-21 8:03 ` Thomas Gleixner
2017-06-21 9:40 ` Borislav Petkov
2017-06-22 11:08 ` [tip:x86/mm] x86/ldt: Simplify the " tip-bot for Andy Lutomirski
2017-06-21 5:22 ` [PATCH v3 03/11] x86/mm: Remove reset_lazy_tlbstate() Andy Lutomirski
2017-06-21 8:03 ` Thomas Gleixner
2017-06-21 9:50 ` Borislav Petkov
2017-06-22 11:08 ` [tip:x86/mm] " tip-bot for Andy Lutomirski
2017-06-21 5:22 ` [PATCH v3 04/11] x86/mm: Give each mm TLB flush generation a unique ID Andy Lutomirski
2017-06-21 8:05 ` Thomas Gleixner
2017-06-21 10:33 ` Borislav Petkov
2017-06-21 15:23 ` Andy Lutomirski
2017-06-21 17:06 ` Borislav Petkov
2017-06-21 17:43 ` Borislav Petkov
2017-06-22 2:34 ` Andy Lutomirski
2017-06-21 5:22 ` [PATCH v3 05/11] x86/mm: Track the TLB's tlb_gen and update the flushing algorithm Andy Lutomirski
2017-06-21 8:32 ` Thomas Gleixner
2017-06-21 15:11 ` Andy Lutomirski
2017-06-21 18:44 ` Borislav Petkov
2017-06-22 2:46 ` Andy Lutomirski
2017-06-22 7:24 ` Borislav Petkov
2017-06-22 14:48 ` Andy Lutomirski
2017-06-22 14:59 ` Borislav Petkov
2017-06-22 15:55 ` Andy Lutomirski
2017-06-22 17:22 ` Borislav Petkov
2017-06-22 18:08 ` Andy Lutomirski
2017-06-23 8:42 ` Borislav Petkov
2017-06-23 15:46 ` Andy Lutomirski
2017-06-21 5:22 ` [PATCH v3 06/11] x86/mm: Rework lazy TLB mode and TLB freshness tracking Andy Lutomirski
2017-06-21 9:01 ` Thomas Gleixner
2017-06-21 16:04 ` Andy Lutomirski
2017-06-21 17:29 ` Borislav Petkov
2017-06-22 14:50 ` Borislav Petkov
2017-06-22 17:47 ` Andy Lutomirski
2017-06-22 19:05 ` Borislav Petkov
2017-07-27 19:53 ` Andrew Banman
2017-07-28 2:05 ` Andy Lutomirski
2017-06-23 13:34 ` Boris Ostrovsky
2017-06-23 15:22 ` Andy Lutomirski
2017-06-21 5:22 ` [PATCH v3 07/11] x86/mm: Stop calling leave_mm() in idle code Andy Lutomirski
2017-06-21 9:22 ` Thomas Gleixner
2017-06-21 15:16 ` Andy Lutomirski
2017-06-23 9:07 ` Borislav Petkov
2017-06-21 5:22 ` [PATCH v3 08/11] x86/mm: Disable PCID on 32-bit kernels Andy Lutomirski
2017-06-21 9:26 ` Thomas Gleixner
2017-06-23 9:24 ` Borislav Petkov
2017-06-21 5:22 ` Andy Lutomirski [this message]
2017-06-21 9:27 ` [PATCH v3 09/11] x86/mm: Add nopcid to turn off PCID Thomas Gleixner
2017-06-23 9:34 ` Borislav Petkov
2017-06-21 5:22 ` [PATCH v3 10/11] x86/mm: Enable CR4.PCIDE on supported systems Andy Lutomirski
2017-06-21 9:39 ` Thomas Gleixner
2017-06-21 13:40 ` Thomas Gleixner
2017-06-21 20:34 ` Andy Lutomirski
2017-06-23 11:50 ` Borislav Petkov
2017-06-23 15:28 ` Andy Lutomirski
2017-06-23 13:35 ` Boris Ostrovsky
2017-06-21 5:22 ` [PATCH v3 11/11] x86/mm: Try to preserve old TLB entries using PCID Andy Lutomirski
2017-06-21 13:38 ` Thomas Gleixner
2017-06-21 13:40 ` Thomas Gleixner
2017-06-22 2:57 ` Andy Lutomirski
2017-06-22 12:21 ` Thomas Gleixner
2017-06-22 18:12 ` Andy Lutomirski
2017-06-22 21:22 ` Thomas Gleixner
2017-06-23 3:09 ` Andy Lutomirski
2017-06-23 7:29 ` Thomas Gleixner
2017-06-22 16:09 ` Nadav Amit
2017-06-22 18:10 ` Andy Lutomirski
2017-06-26 15:58 ` Borislav Petkov
2017-06-21 18:23 ` [PATCH v3 00/11] PCID and improved laziness Linus Torvalds
2017-06-22 5:19 ` Andy Lutomirski
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