Commit 3841cdc3 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar

sched/fair: Fix comments

Historically our periods (or p) argument in PELT denoted the number of
full periods (what is now d2). However recent patches have changed
this to the total decay (previously p+1), leading to a confusing
discrepancy between comments and code.

Try and clarify things by making periods (in code) and p (in comments)
be the same thing (again).
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 76d034ed
......@@ -2777,18 +2777,18 @@ static u32 __accumulate_pelt_segments(u64 periods, u32 d1, u32 d3)
u32 c1, c2, c3 = d3; /* y^0 == 1 */
/*
* c1 = d1 y^(p+1)
* c1 = d1 y^p
*/
c1 = decay_load((u64)d1, periods);
/*
* p
* p-1
* c2 = 1024 \Sum y^n
* n=1
*
* inf inf
* = 1024 ( \Sum y^n - \Sum y^n - y^0 )
* n=0 n=p+1
* n=0 n=p
*/
c2 = LOAD_AVG_MAX - decay_load(LOAD_AVG_MAX, periods) - 1024;
......@@ -2808,14 +2808,14 @@ static u32 __accumulate_pelt_segments(u64 periods, u32 d1, u32 d3)
* |<->|<----------------->|<--->|
* ... |---x---|------| ... |------|-----x (now)
*
* p
* u' = (u + d1) y^(p+1) + 1024 \Sum y^n + d3 y^0
* p-1
* u' = (u + d1) y^p + 1024 \Sum y^n + d3 y^0
* n=1
*
* = u y^(p+1) + (Step 1)
* = u y^p + (Step 1)
*
* p
* d1 y^(p+1) + 1024 \Sum y^n + d3 y^0 (Step 2)
* p-1
* d1 y^p + 1024 \Sum y^n + d3 y^0 (Step 2)
* n=1
*/
static __always_inline u32
......
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