/*
* Copyright (c) 2014 Red Hat, Inc.
* All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it would be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef __XFS_RMAP_BTREE_H__
#define __XFS_RMAP_BTREE_H__
struct xfs_buf;
struct xfs_btree_cur;
struct xfs_mount;
/* rmaps only exist on crc enabled filesystems */
#define XFS_RMAP_BLOCK_LEN XFS_BTREE_SBLOCK_CRC_LEN
/*
* Record, key, and pointer address macros for btree blocks.
*
* (note that some of these may appear unused, but they are used in userspace)
*/
#define XFS_RMAP_REC_ADDR(block, index) \
((struct xfs_rmap_rec *) \
((char *)(block) + XFS_RMAP_BLOCK_LEN + \
(((index) - 1) * sizeof(struct xfs_rmap_rec))))
#define XFS_RMAP_KEY_ADDR(block, index) \
((struct xfs_rmap_key *) \
((char *)(block) + XFS_RMAP_BLOCK_LEN + \
((index) - 1) * 2 * sizeof(struct xfs_rmap_key)))
#define XFS_RMAP_HIGH_KEY_ADDR(block, index) \
((struct xfs_rmap_key *) \
((char *)(block) + XFS_RMAP_BLOCK_LEN + \
sizeof(struct xfs_rmap_key) + \
((index) - 1) * 2 * sizeof(struct xfs_rmap_key)))
#define XFS_RMAP_PTR_ADDR(block, index, maxrecs) \
((xfs_rmap_ptr_t *) \
((char *)(block) + XFS_RMAP_BLOCK_LEN + \
(maxrecs) * 2 * sizeof(struct xfs_rmap_key) + \
((index) - 1) * sizeof(xfs_rmap_ptr_t)))
struct xfs_btree_cur *xfs_rmapbt_init_cursor(struct xfs_mount *mp,
struct xfs_trans *tp, struct xfs_buf *bp,
xfs_agnumber_t agno);
int xfs_rmapbt_maxrecs(struct xfs_mount *mp, int blocklen, int leaf);
extern void xfs_rmapbt_compute_maxlevels(struct xfs_mount *mp);
extern xfs_extlen_t xfs_rmapbt_calc_size(struct xfs_mount *mp,
unsigned long long len);
extern xfs_extlen_t xfs_rmapbt_max_size(struct xfs_mount *mp,
xfs_agblock_t agblocks);
extern int xfs_rmapbt_calc_reserves(struct xfs_mount *mp,
xfs_agnumber_t agno, xfs_extlen_t *ask, xfs_extlen_t *used);
#endif /* __XFS_RMAP_BTREE_H__ */
ommitter
cpufreq: intel_pstate: Disable energy efficiency optimization
Some Kabylake desktop processors may not reach max turbo when running in
HWP mode, even if running under sustained 100% utilization.
This occurs when the HWP.EPP (Energy Performance Preference) is set to
"balance_power" (0x80) -- the default on most systems.
It occurs because the platform BIOS may erroneously enable an
energy-efficiency setting -- MSR_IA32_POWER_CTL BIT-EE, which is not
recommended to be enabled on this SKU.
On the failing systems, this BIOS issue was not discovered when the
desktop motherboard was tested with Windows, because the BIOS also
neglects to provide the ACPI/CPPC table, that Windows requires to enable
HWP, and so Windows runs in legacy P-state mode, where this setting has
no effect.
Linux' intel_pstate driver does not require ACPI/CPPC to enable HWP, and
so it runs in HWP mode, exposing this incorrect BIOS configuration.
There are several ways to address this problem.
First, Linux can also run in legacy P-state mode on this system.
As intel_pstate is how Linux enables HWP, booting with
"intel_pstate=disable"
will run in acpi-cpufreq/ondemand legacy p-state mode.
Or second, the "performance" governor can be used with intel_pstate,
which will modify HWP.EPP to 0.
Or third, starting in 4.10, the
/sys/devices/system/cpu/cpufreq/policy*/energy_performance_preference
attribute in can be updated from "balance_power" to "performance".
Or fourth, apply this patch, which fixes the erroneous setting of
MSR_IA32_POWER_CTL BIT_EE on this model, allowing the default
configuration to function as designed.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Reviewed-by: Len Brown <len.brown@intel.com>
Cc: 4.6+ <stable@vger.kernel.org> # 4.6+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>