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14ae42a6f0
Since commit 5768402fd9c6 ("perf/ring_buffer: Use high order allocations
for AUX buffers optimistically"), the perf core tends to back aux buffer
allocations with high-order pages with the order encoded in the
PagePrivate data. The Arm SPE driver explicitly rejects such pages,
causing the perf tool to fail with:
| failed to mmap with 12 (Cannot allocate memory)
In actual fact, we can simply treat these pages just like any other
since the perf core takes care to populate the page array appropriately.
In theory we could try to map with PMDs where possible, but for now,
let's just get things working again.
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Fixes: 5768402fd9c6 ("perf/ring_buffer: Use high order allocations for AUX buffers optimistically")
Reported-by: Hanjun Guo <guohanjun@huawei.com>
Tested-by: Hanjun Guo <guohanjun@huawei.com>
Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.