Commit 5a88a6e9 authored by Reinette Chatre's avatar Reinette Chatre Committed by Borislav Petkov (AMD)
Browse files

fs/resctrl: Consider sparse masks when initializing new group's allocation 



A new resource group is intended to be created with sane defaults. For a cache
resource this means all cache portions the new group could possibly allocate
into. This includes unused cache portions and shareable cache portions used by
other groups and hardware.

New resource group creation does not take sparse masks into account. After
determining the bitmask reflecting the new group's possible allocations the
bitmask is forced to be contiguous even if the system supports sparse masks.
For example, a new group could by default allocate into a large portion of
cache represented by 0xff0f, but it is instead created with a mask of 0xf.

Do not force a contiguous allocation range if the system supports sparse masks.

Signed-off-by: default avatarReinette Chatre <reinette.chatre@intel.com>
Signed-off-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Link: https://patch.msgid.link/abbbb008bc09d982d715e79d3b885c10f92c64e0.1763426240.git.reinette.chatre@intel.com
parent a0a09995

fs/resctrl/rdtgroup.c

+4 −3
Original line number Diff line number Diff line
@@ -3383,11 +3383,12 @@ static u32 cbm_ensure_valid(u32 _val, struct rdt_resource *r) 
{

	unsigned int cbm_len = r->cache.cbm_len;

	unsigned long first_bit, zero_bit;

	unsigned long val = _val;

	unsigned long val;



	if (!val)

		return 0;

	if (!_val || r->cache.arch_has_sparse_bitmasks)

		return _val;



	val = _val;

	first_bit = find_first_bit(&val, cbm_len);

	zero_bit = find_next_zero_bit(&val, cbm_len, first_bit);