From: Dan Williams <dan.j.williams@intel.com>
To: Oscar Salvador <osalvador@suse.de>, Gregory Price <gourry@gourry.net>
Cc: <linux-mm@kvack.org>, <linux-acpi@vger.kernel.org>,
<kernel-team@meta.com>, <x86@kernel.org>,
<linux-kernel@vger.kernel.org>, <dave.hansen@linux.intel.com>,
<luto@kernel.org>, <peterz@infradead.org>, <tglx@linutronix.de>,
<mingo@redhat.com>, <bp@alien8.de>, <hpa@zytor.com>,
<rafael@kernel.org>, <lenb@kernel.org>, <david@redhat.com>,
<gregkh@linuxfoundation.org>, <akpm@linux-foundation.org>,
<dan.j.williams@intel.com>, <Jonathan.Cameron@huawei.com>,
<alison.schofield@intel.com>, <rrichter@amd.com>,
<rppt@kernel.org>, <bfaccini@nvidia.com>, <haibo1.xu@intel.com>,
<dave.jiang@intel.com>, "Ira Weiny" <ira.weiny@intel.com>,
Fan Ni <fan.ni@samsung.com>
Subject: Re: [PATCH v8 0/3] memory,x86,acpi: hotplug memory alignment advisement
Date: Tue, 1 Apr 2025 12:44:26 -0700 [thread overview]
Message-ID: <67ec421a15fe8_288d294c9@dwillia2-xfh.jf.intel.com.notmuch> (raw)
In-Reply-To: <Z-w2O8O9MGJ1Ok78@localhost.localdomain>
Oscar Salvador wrote:
> On Mon, Jan 27, 2025 at 10:34:02AM -0500, Gregory Price wrote:
> > v8: nits and tag pickups
> >
> > When physical address regions are not aligned to memory block size,
> > the misaligned portion is lost (stranded capacity).
> >
> > Block size (min/max/selected) is architecture defined. Most architectures
> > tend to use the minimum block size or some simplistic heurist. On x86,
> > memory block size increases up to 2GB, and is otherwise fitted to the
> > alignment of non-hotplug (i.e. not special purpose memory).
>
> I wonder if something like this could help us in improving the
> ridiculous situation of having 16MB memory-block size on powerpc.
It's only ridiculous due to what it does to /sys/.../memory,
right?
If you permit me a bit of hand-waving, it would be lovely to deprecate
/sys/.../memory in favor of a new (fd based?) ABI for memory-hotplug
policy management and have something like a fuse "compatfs" mounted at
/sys/.../memory/ for maintaining legacy compatibility for userspace that
still depends on twiddling with individual blocks in sysfs.
prev parent reply other threads:[~2025-04-01 19:44 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-01-27 15:34 Gregory Price
2025-01-27 15:34 ` [PATCH v8 1/3] memory: implement memory_block_advise/probe_max_size Gregory Price
2025-04-01 18:50 ` Oscar Salvador
2025-01-27 15:34 ` [PATCH v8 2/3] x86: probe memory block size advisement value during mm init Gregory Price
2025-04-01 18:51 ` Oscar Salvador
2025-01-27 15:34 ` [PATCH v8 3/3] acpi,srat: give memory block size advice based on CFMWS alignment Gregory Price
2025-04-01 18:52 ` Oscar Salvador
2025-04-01 18:33 ` [PATCH v8 0/3] memory,x86,acpi: hotplug memory alignment advisement Gregory Price
2025-04-01 18:53 ` Oscar Salvador
2025-04-01 19:08 ` David Hildenbrand
2025-04-02 9:39 ` Mike Rapoport
2025-04-02 10:07 ` David Hildenbrand
2025-04-01 19:44 ` Dan Williams [this message]
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