From: Peter Zijlstra <peterz@infradead.org>
To: Dave Hansen <dave.hansen@linux.intel.com>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
hughd@google.com, moritz.lipp@iaik.tugraz.at,
daniel.gruss@iaik.tugraz.at, michael.schwarz@iaik.tugraz.at,
richard.fellner@student.tugraz.at, luto@kernel.org,
torvalds@linux-foundation.org, keescook@google.com,
x86@kernel.org
Subject: Re: [PATCH 18/30] x86, kaiser: map virtually-addressed performance monitoring buffers
Date: Fri, 10 Nov 2017 13:17:56 +0100 [thread overview]
Message-ID: <20171110121756.t7mn7bb4gy3rnw2w@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20171108194720.0ADD17E2@viggo.jf.intel.com>
On Wed, Nov 08, 2017 at 11:47:20AM -0800, Dave Hansen wrote:
> +static
> +DEFINE_PER_CPU_SHARED_ALIGNED_USER_MAPPED(struct debug_store, cpu_debug_store);
> +
> /* The size of a BTS record in bytes: */
> #define BTS_RECORD_SIZE 24
>
> @@ -278,6 +282,39 @@ void fini_debug_store_on_cpu(int cpu)
>
> static DEFINE_PER_CPU(void *, insn_buffer);
>
> +static void *dsalloc(size_t size, gfp_t flags, int node)
> +{
> +#ifdef CONFIG_KAISER
> + unsigned int order = get_order(size);
> + struct page *page;
> + unsigned long addr;
> +
> + page = __alloc_pages_node(node, flags | __GFP_ZERO, order);
> + if (!page)
> + return NULL;
> + addr = (unsigned long)page_address(page);
> + if (kaiser_add_mapping(addr, size, __PAGE_KERNEL | _PAGE_GLOBAL) < 0) {
> + __free_pages(page, order);
> + addr = 0;
> + }
> + return (void *)addr;
> +#else
> + return kmalloc_node(size, flags | __GFP_ZERO, node);
> +#endif
> +}
> +
> +static void dsfree(const void *buffer, size_t size)
> +{
> +#ifdef CONFIG_KAISER
> + if (!buffer)
> + return;
> + kaiser_remove_mapping((unsigned long)buffer, size);
> + free_pages((unsigned long)buffer, get_order(size));
> +#else
> + kfree(buffer);
> +#endif
> +}
You might as well use __alloc_pages_node() / free_pages()
unconditionally. Those buffers are at least one page in size.
That should also get rid of the #ifdef muck.
> static int alloc_ds_buffer(int cpu)
> {
> - int node = cpu_to_node(cpu);
> - struct debug_store *ds;
> -
> - ds = kzalloc_node(sizeof(*ds), GFP_KERNEL, node);
> - if (unlikely(!ds))
> - return -ENOMEM;
> + struct debug_store *ds = per_cpu_ptr(&cpu_debug_store, cpu);
>
> + memset(ds, 0, sizeof(*ds));
Why the memset() ? isn't static per-cpu memory 0 initialized
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next prev parent reply other threads:[~2017-11-10 12:18 UTC|newest]
Thread overview: 68+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-08 19:46 [PATCH 00/30] [v2] KAISER: unmap most of the kernel from userspace page tables Dave Hansen
2017-11-08 19:46 ` [PATCH 01/30] x86, mm: do not set _PAGE_USER for init_mm " Dave Hansen
2017-11-08 19:52 ` Linus Torvalds
2017-11-08 20:11 ` Dave Hansen
2017-11-09 10:29 ` Borislav Petkov
2017-11-08 19:46 ` [PATCH 02/30] x86, tlb: make CR4-based TLB flushes more robust Dave Hansen
2017-11-09 10:48 ` Borislav Petkov
2017-11-09 10:51 ` Thomas Gleixner
2017-11-09 11:02 ` Borislav Petkov
2017-11-08 19:46 ` [PATCH 03/30] x86, mm: document X86_CR4_PGE toggling behavior Dave Hansen
2017-11-09 12:21 ` Borislav Petkov
2017-11-08 19:46 ` [PATCH 04/30] x86, kaiser: disable global pages by default with KAISER Dave Hansen
2017-11-09 12:51 ` Borislav Petkov
2017-11-09 22:19 ` Thomas Gleixner
2017-11-08 19:46 ` [PATCH 05/30] x86, kaiser: prepare assembly for entry/exit CR3 switching Dave Hansen
2017-11-09 13:20 ` Borislav Petkov
2017-11-09 15:34 ` Dave Hansen
2017-11-09 15:59 ` Borislav Petkov
2017-11-08 19:46 ` [PATCH 06/30] x86, kaiser: introduce user-mapped percpu areas Dave Hansen
2017-11-08 19:46 ` [PATCH 07/30] x86, kaiser: mark percpu data structures required for entry/exit Dave Hansen
2017-11-08 19:47 ` [PATCH 08/30] x86, kaiser: unmap kernel from userspace page tables (core patch) Dave Hansen
2017-11-10 12:57 ` Ingo Molnar
2017-11-08 19:47 ` [PATCH 09/30] x86, kaiser: only populate shadow page tables for userspace Dave Hansen
2017-11-08 19:47 ` [PATCH 10/30] x86, kaiser: allow NX to be set in p4d/pgd Dave Hansen
2017-11-08 19:47 ` [PATCH 11/30] x86, kaiser: make sure static PGDs are 8k in size Dave Hansen
2017-11-08 19:47 ` [PATCH 12/30] x86, kaiser: map GDT into user page tables Dave Hansen
2017-11-08 19:47 ` [PATCH 13/30] x86, kaiser: map dynamically-allocated LDTs Dave Hansen
2017-11-08 19:47 ` [PATCH 14/30] x86, kaiser: map espfix structures Dave Hansen
2017-11-08 19:47 ` [PATCH 15/30] x86, kaiser: map entry stack variables Dave Hansen
2017-11-08 19:47 ` [PATCH 16/30] x86, kaiser: map trace interrupt entry Dave Hansen
2017-11-08 19:47 ` [PATCH 17/30] x86, kaiser: map debug IDT tables Dave Hansen
2017-11-08 19:47 ` [PATCH 18/30] x86, kaiser: map virtually-addressed performance monitoring buffers Dave Hansen
2017-11-10 12:17 ` Peter Zijlstra [this message]
2017-11-08 19:47 ` [PATCH 19/30] x86, mm: Move CR3 construction functions Dave Hansen
2017-11-08 19:47 ` [PATCH 20/30] x86, mm: remove hard-coded ASID limit checks Dave Hansen
2017-11-10 12:20 ` Peter Zijlstra
2017-11-10 18:41 ` Dave Hansen
2017-11-08 19:47 ` [PATCH 21/30] x86, mm: put mmu-to-h/w ASID translation in one place Dave Hansen
2017-11-08 19:47 ` [PATCH 22/30] x86, pcid, kaiser: allow flushing for future ASID switches Dave Hansen
2017-11-10 12:25 ` Peter Zijlstra
2017-11-08 19:47 ` [PATCH 23/30] x86, kaiser: use PCID feature to make user and kernel switches faster Dave Hansen
2017-11-08 19:47 ` [PATCH 24/30] x86, kaiser: disable native VSYSCALL Dave Hansen
2017-11-09 19:04 ` Andy Lutomirski
2017-11-09 19:26 ` Dave Hansen
2017-11-10 0:53 ` Andy Lutomirski
2017-11-10 0:57 ` Dave Hansen
2017-11-10 1:04 ` Andy Lutomirski
2017-11-10 1:22 ` Dave Hansen
2017-11-10 2:25 ` Andy Lutomirski
2017-11-10 6:31 ` Dave Hansen
2017-11-10 22:06 ` Andy Lutomirski
2017-11-10 23:04 ` Dave Hansen
2017-11-13 3:52 ` Andy Lutomirski
2017-11-13 21:07 ` Dave Hansen
2017-11-14 2:15 ` Andy Lutomirski
2017-11-08 19:47 ` [PATCH 25/30] x86, kaiser: add debugfs file to turn KAISER on/off at runtime Dave Hansen
2017-11-08 19:47 ` [PATCH 26/30] x86, kaiser: add a function to check for KAISER being enabled Dave Hansen
2017-11-08 19:47 ` [PATCH 27/30] x86, kaiser: un-poison PGDs at runtime Dave Hansen
2017-11-08 19:47 ` [PATCH 28/30] x86, kaiser: allow KAISER to be enabled/disabled " Dave Hansen
2017-11-08 19:47 ` [PATCH 29/30] x86, kaiser: add Kconfig Dave Hansen
2017-11-08 19:47 ` [PATCH 30/30] x86, kaiser, xen: Dynamically disable KAISER when running under Xen PV Dave Hansen
2017-11-09 15:01 ` Juergen Gross
2017-11-10 19:30 [PATCH 00/30] [v3] KAISER: unmap most of the kernel from userspace page tables Dave Hansen
2017-11-10 19:31 ` [PATCH 18/30] x86, kaiser: map virtually-addressed performance monitoring buffers Dave Hansen
2017-11-14 18:20 ` Peter Zijlstra
2017-11-14 18:28 ` Dave Hansen
2017-11-14 19:10 ` Hugh Dickins
2017-11-14 19:24 ` Andy Lutomirski
2017-11-15 9:41 ` Peter Zijlstra
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