Adrian Hunter 9bed6852d3 perf: Fix default aux_watermark calculation
[ Upstream commit 43deb76b19663a96ec2189d8f4eb9a9dc2d7623f ]

The default aux_watermark is half the AUX area buffer size. In general,
on a 64-bit architecture, the AUX area buffer size could be a bigger than
fits in a 32-bit type, but the calculation does not allow for that
possibility.

However the aux_watermark value is recorded in a u32, so should not be
more than U32_MAX either.

Fix by doing the calculation in a correctly sized type, and limiting the
result to U32_MAX.

Fixes: d68e6799a5c8 ("perf: Cap allocation order at aux_watermark")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240624201101.60186-7-adrian.hunter@intel.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-03 08:59:43 +02:00
..
2022-02-25 09:36:06 +01:00
2024-05-17 18:29:30 -07:00