From: Peter Zijlstra <peterz@infradead.org>
To: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>,
Andy Lutomirski <luto@kernel.org>,
x86@kernel.org, Kostya Serebryany <kcc@google.com>,
Andrey Ryabinin <ryabinin.a.a@gmail.com>,
Andrey Konovalov <andreyknvl@gmail.com>,
Alexander Potapenko <glider@google.com>,
Taras Madan <tarasmadan@google.com>,
Dmitry Vyukov <dvyukov@google.com>,
"H . J . Lu" <hjl.tools@gmail.com>,
Andi Kleen <ak@linux.intel.com>,
Rick Edgecombe <rick.p.edgecombe@intel.com>,
Bharata B Rao <bharata@amd.com>,
Jacob Pan <jacob.jun.pan@linux.intel.com>,
Ashok Raj <ashok.raj@intel.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCHv14 08/17] x86/mm: Reduce untagged_addr() overhead until the first LAM user
Date: Tue, 17 Jan 2023 14:05:22 +0100 [thread overview]
Message-ID: <Y8adEg2CYUSVpwtk@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20230111123736.20025-9-kirill.shutemov@linux.intel.com>
On Wed, Jan 11, 2023 at 03:37:27PM +0300, Kirill A. Shutemov wrote:
> #define __untagged_addr(untag_mask, addr) ({ \
> u64 __addr = (__force u64)(addr); \
> - s64 sign = (s64)__addr >> 63; \
> - __addr &= untag_mask | sign; \
> + if (static_branch_likely(&tagged_addr_key)) { \
> + s64 sign = (s64)__addr >> 63; \
> + __addr &= untag_mask | sign; \
> + } \
> (__force __typeof__(addr))__addr; \
> })
>
> #define untagged_addr(addr) __untagged_addr(current_untag_mask(), addr)
Is the compiler clever enough to put the memop inside the branch?
next prev parent reply other threads:[~2023-01-17 13:05 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-11 12:37 [PATCHv14 00/17] Linear Address Masking enabling Kirill A. Shutemov
2023-01-11 12:37 ` [PATCHv14 01/17] x86/mm: Rework address range check in get_user() and put_user() Kirill A. Shutemov
2023-01-18 15:49 ` Peter Zijlstra
2023-01-18 15:59 ` Linus Torvalds
2023-01-18 16:48 ` Peter Zijlstra
2023-01-18 17:01 ` Linus Torvalds
2023-01-11 12:37 ` [PATCHv14 02/17] x86: Allow atomic MM_CONTEXT flags setting Kirill A. Shutemov
2023-01-11 12:37 ` [PATCHv14 03/17] x86: CPUID and CR3/CR4 flags for Linear Address Masking Kirill A. Shutemov
2023-01-11 12:37 ` [PATCHv14 04/17] x86/mm: Handle LAM on context switch Kirill A. Shutemov
2023-01-11 13:49 ` Linus Torvalds
2023-01-11 14:14 ` Kirill A. Shutemov
2023-01-11 14:37 ` [PATCHv14.1 " Kirill A. Shutemov
2023-01-11 12:37 ` [PATCHv14 05/17] mm: Introduce untagged_addr_remote() Kirill A. Shutemov
2023-01-11 12:37 ` [PATCHv14 06/17] x86/uaccess: Provide untagged_addr() and remove tags before address check Kirill A. Shutemov
2023-01-11 12:37 ` [PATCHv14 07/17] x86/mm: Provide arch_prctl() interface for LAM Kirill A. Shutemov
2023-01-11 12:37 ` [PATCHv14 08/17] x86/mm: Reduce untagged_addr() overhead until the first LAM user Kirill A. Shutemov
2023-01-17 13:05 ` Peter Zijlstra [this message]
2023-01-17 13:57 ` Kirill A. Shutemov
2023-01-17 15:02 ` Peter Zijlstra
2023-01-17 17:18 ` Linus Torvalds
2023-01-17 17:28 ` Linus Torvalds
2023-01-17 18:26 ` Nick Desaulniers
2023-01-17 18:33 ` Linus Torvalds
2023-01-17 19:17 ` Nick Desaulniers
2023-01-17 20:10 ` Linus Torvalds
2023-01-17 20:43 ` Linus Torvalds
2023-01-17 18:14 ` Peter Zijlstra
2023-01-17 18:21 ` Peter Zijlstra
2023-01-19 23:06 ` Kirill A. Shutemov
2023-01-11 12:37 ` [PATCHv14 09/17] mm: Expose untagging mask in /proc/$PID/status Kirill A. Shutemov
2023-01-11 12:37 ` [PATCHv14 10/17] iommu/sva: Replace pasid_valid() helper with mm_valid_pasid() Kirill A. Shutemov
2023-01-11 12:37 ` [PATCHv14 11/17] x86/mm/iommu/sva: Make LAM and SVA mutually exclusive Kirill A. Shutemov
2023-01-11 12:37 ` [PATCHv14 12/17] selftests/x86/lam: Add malloc and tag-bits test cases for linear-address masking Kirill A. Shutemov
2023-01-11 12:37 ` [PATCHv14 13/17] selftests/x86/lam: Add mmap and SYSCALL " Kirill A. Shutemov
2023-01-11 12:37 ` [PATCHv14 14/17] selftests/x86/lam: Add io_uring " Kirill A. Shutemov
2023-01-11 12:37 ` [PATCHv14 15/17] selftests/x86/lam: Add inherit " Kirill A. Shutemov
2023-01-11 12:37 ` [PATCHv14 16/17] selftests/x86/lam: Add ARCH_FORCE_TAGGED_SVA " Kirill A. Shutemov
2023-01-11 12:37 ` [PATCHv14 17/17] selftests/x86/lam: Add test cases for LAM vs thread creation Kirill A. Shutemov
2023-01-18 16:49 ` [PATCHv14 00/17] Linear Address Masking enabling Peter Zijlstra
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