Re: [PATCH 8/9] psi: pressure stall information for CPU, memory, and IO
From: Peter Zijlstra <peterz@infradead.org>
Date: 2018-08-06 16:03:43
Also in:
linux-mm, lkml
Possibly related (same subject, not in this thread)
- 2018-09-07 · Re: [PATCH 8/9] psi: pressure stall information for CPU, memory, and IO · Johannes Weiner <hannes@cmpxchg.org>
- 2018-09-07 · Re: [PATCH 8/9] psi: pressure stall information for CPU, memory, and IO · Peter Zijlstra <peterz@infradead.org>
- 2018-09-07 · Re: [PATCH 8/9] psi: pressure stall information for CPU, memory, and IO · Johannes Weiner <hannes@cmpxchg.org>
- 2018-09-07 · Re: [PATCH 8/9] psi: pressure stall information for CPU, memory, and IO · Johannes Weiner <hannes@cmpxchg.org>
- 2018-09-07 · Re: [PATCH 8/9] psi: pressure stall information for CPU, memory, and IO · Peter Zijlstra <peterz@infradead.org>
On Mon, Aug 06, 2018 at 11:19:28AM -0400, Johannes Weiner wrote:
On Fri, Aug 03, 2018 at 06:56:41PM +0200, Peter Zijlstra wrote:quoted
On Wed, Aug 01, 2018 at 11:19:57AM -0400, Johannes Weiner wrote:
quoted
quoted
+ u32 uninitialized_var(nonidle);urgh.. I can see why the compiler got confused. Dodgy :-):-) I think we can make this cleaner. Something like this (modulo the READ_ONCE/WRITE_ONCE you pointed out in the other email)?
quoted hunk ↗ jump to hunk
@@ -244,60 +287,17 @@ static bool psi_update_stats(struct psi_group *group) */ for_each_online_cpu(cpu) { struct psi_group_cpu *groupc = per_cpu_ptr(group->pcpu, cpu); + u32 nonidle; + + nonidle = read_update_delta(groupc, PSI_NONIDLE, cpu); + nonidle = nsecs_to_jiffies(nonidle); + nonidle_total += nonidle; + + for (s = 0; s < PSI_NONIDLE; s++) { + u32 delta; + + delta = read_update_delta(groupc, s, cpu); + deltas[s] += (u64)delta * nonidle; } }
Yes, much clearer, thanks!