[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20240719172849.000019a0@Huawei.com>
Date: Fri, 19 Jul 2024 17:28:49 +0100
From: Jonathan Cameron <Jonathan.Cameron@...wei.com>
To: Mike Rapoport <rppt@...nel.org>
CC: <linux-kernel@...r.kernel.org>, Alexander Gordeev
<agordeev@...ux.ibm.com>, Andreas Larsson <andreas@...sler.com>, "Andrew
Morton" <akpm@...ux-foundation.org>, Arnd Bergmann <arnd@...db.de>, "Borislav
Petkov" <bp@...en8.de>, Catalin Marinas <catalin.marinas@....com>, Christophe
Leroy <christophe.leroy@...roup.eu>, Dan Williams <dan.j.williams@...el.com>,
Dave Hansen <dave.hansen@...ux.intel.com>, David Hildenbrand
<david@...hat.com>, "David S. Miller" <davem@...emloft.net>, Greg
Kroah-Hartman <gregkh@...uxfoundation.org>, Heiko Carstens
<hca@...ux.ibm.com>, Huacai Chen <chenhuacai@...nel.org>, Ingo Molnar
<mingo@...hat.com>, Jiaxun Yang <jiaxun.yang@...goat.com>, "John Paul Adrian
Glaubitz" <glaubitz@...sik.fu-berlin.de>, Michael Ellerman
<mpe@...erman.id.au>, Palmer Dabbelt <palmer@...belt.com>, "Rafael J.
Wysocki" <rafael@...nel.org>, Rob Herring <robh@...nel.org>, "Thomas
Bogendoerfer" <tsbogend@...ha.franken.de>, Thomas Gleixner
<tglx@...utronix.de>, Vasily Gorbik <gor@...ux.ibm.com>, Will Deacon
<will@...nel.org>, <linux-arm-kernel@...ts.infradead.org>,
<loongarch@...ts.linux.dev>, <linux-mips@...r.kernel.org>,
<linuxppc-dev@...ts.ozlabs.org>, <linux-riscv@...ts.infradead.org>,
<linux-s390@...r.kernel.org>, <linux-sh@...r.kernel.org>,
<sparclinux@...r.kernel.org>, <linux-acpi@...r.kernel.org>,
<linux-cxl@...r.kernel.org>, <nvdimm@...ts.linux.dev>,
<devicetree@...r.kernel.org>, <linux-arch@...r.kernel.org>,
<linux-mm@...ck.org>, <x86@...nel.org>
Subject: Re: [PATCH 06/17] x86/numa: simplify numa_distance allocation
On Tue, 16 Jul 2024 14:13:35 +0300
Mike Rapoport <rppt@...nel.org> wrote:
> From: "Mike Rapoport (Microsoft)" <rppt@...nel.org>
>
> Allocation of numa_distance uses memblock_phys_alloc_range() to limit
> allocation to be below the last mapped page.
>
> But NUMA initializaition runs after the direct map is populated and
initialization (one too many 'i's)
> there is also code in setup_arch() that adjusts memblock limit to
> reflect how much memory is already mapped in the direct map.
>
> Simplify the allocation of numa_distance and use plain memblock_alloc().
> This makes the code clearer and ensures that when numa_distance is not
> allocated it is always NULL.
Doesn't this break the comment in numa_set_distance() kernel-doc?
"
* If such table cannot be allocated, a warning is printed and further
* calls are ignored until the distance table is reset with
* numa_reset_distance().
"
Superficially that looks to be to avoid repeatedly hitting the
singleton bit at the top of numa_set_distance() as SRAT or similar
parsing occurs.
>
> Signed-off-by: Mike Rapoport (Microsoft) <rppt@...nel.org>
> ---
> arch/x86/mm/numa.c | 12 +++---------
> 1 file changed, 3 insertions(+), 9 deletions(-)
>
> diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
> index 5e1dde26674b..ab2d4ecef786 100644
> --- a/arch/x86/mm/numa.c
> +++ b/arch/x86/mm/numa.c
> @@ -319,8 +319,7 @@ void __init numa_reset_distance(void)
> {
> size_t size = numa_distance_cnt * numa_distance_cnt * sizeof(numa_distance[0]);
>
> - /* numa_distance could be 1LU marking allocation failure, test cnt */
> - if (numa_distance_cnt)
> + if (numa_distance)
> memblock_free(numa_distance, size);
> numa_distance_cnt = 0;
> numa_distance = NULL; /* enable table creation */
> @@ -331,7 +330,6 @@ static int __init numa_alloc_distance(void)
> nodemask_t nodes_parsed;
> size_t size;
> int i, j, cnt = 0;
> - u64 phys;
>
> /* size the new table and allocate it */
> nodes_parsed = numa_nodes_parsed;
> @@ -342,16 +340,12 @@ static int __init numa_alloc_distance(void)
> cnt++;
> size = cnt * cnt * sizeof(numa_distance[0]);
>
> - phys = memblock_phys_alloc_range(size, PAGE_SIZE, 0,
> - PFN_PHYS(max_pfn_mapped));
> - if (!phys) {
> + numa_distance = memblock_alloc(size, PAGE_SIZE);
> + if (!numa_distance) {
> pr_warn("Warning: can't allocate distance table!\n");
> - /* don't retry until explicitly reset */
> - numa_distance = (void *)1LU;
> return -ENOMEM;
> }
>
> - numa_distance = __va(phys);
> numa_distance_cnt = cnt;
>
> /* fill with the default distances */
Powered by blists - more mailing lists