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pkt_sched: Use PSCHED_SHIFT in PSCHED time conversion

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Use PSCHED_SHIFT constant instead of '10' in PSCHED_US2NS() and
PSCHED_NS2US() macros to enable changing this value later.

Additionally use PSCHED_SHIFT in sch_hfsc SM_SHIFT and ISM_SHIFT
definitions. This part of the patch is based on feedback from
Patrick McHardy <kaber@trash.net>.

Reported-by: Antonio Almeida <vexwek@gmail.com>
Tested-by: Antonio Almeida <vexwek@gmail.com>
Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jarek Poplawski 2009-06-08 22:05:00 +00:00 committed by David S. Miller
parent 0c27922e49
commit 728bf09827
2 changed files with 8 additions and 5 deletions
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5
include/net/pkt_sched.h
View File

@ -42,8 +42,9 @@ typedef u64 psched_time_t;
typedef long psched_tdiff_t;
/* Avoid doing 64 bit divide by 1000 */
#define PSCHED_US2NS(x) ((s64)(x) << 10)
#define PSCHED_NS2US(x) ((x) >> 10)
#define PSCHED_SHIFT 10
#define PSCHED_US2NS(x) ((s64)(x) << PSCHED_SHIFT)
#define PSCHED_NS2US(x) ((x) >> PSCHED_SHIFT)
#define PSCHED_TICKS_PER_SEC PSCHED_NS2US(NSEC_PER_SEC)
#define PSCHED_PASTPERFECT 0

8
net/sched/sch_hfsc.c
View File

@ -372,7 +372,7 @@ cftree_update(struct hfsc_class *cl)
* ism: (psched_us/byte) << ISM_SHIFT
* dx: psched_us
*
* The clock source resolution with ktime is 1.024us.
* The clock source resolution with ktime and PSCHED_SHIFT 10 is 1.024us.
*
* sm and ism are scaled in order to keep effective digits.
* SM_SHIFT and ISM_SHIFT are selected to keep at least 4 effective
@ -383,9 +383,11 @@ cftree_update(struct hfsc_class *cl)
* bytes/1.024us 12.8e-3 128e-3 1280e-3 12800e-3 128000e-3
*
* 1.024us/byte 78.125 7.8125 0.78125 0.078125 0.0078125
*
* So, for PSCHED_SHIFT 10 we need: SM_SHIFT 20, ISM_SHIFT 18.
*/
#define SM_SHIFT 20
#define ISM_SHIFT 18
#define SM_SHIFT (30 - PSCHED_SHIFT)
#define ISM_SHIFT (8 + PSCHED_SHIFT)
#define SM_MASK ((1ULL << SM_SHIFT) - 1)
#define ISM_MASK ((1ULL << ISM_SHIFT) - 1)