From: Marcelo Tosatti <mtosatti@redhat.com>
To: Christoph Lameter <cl@linux.com>
Cc: Aaron Tomlin <atomlin@atomlin.com>,
Frederic Weisbecker <frederic@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
Russell King <linux@armlinux.org.uk>,
Huacai Chen <chenhuacai@kernel.org>,
Heiko Carstens <hca@linux.ibm.com>,
x86@kernel.org, Marcelo Tosatti <mtosatti@redhat.com>
Subject: [PATCH v4 10/12] mm/vmstat: use xchg in cpu_vm_stats_fold
Date: Sun, 05 Mar 2023 10:37:07 -0300 [thread overview]
Message-ID: <20230305134053.663216906@redhat.com> (raw)
In-Reply-To: <20230305133657.255737580@redhat.com>
In preparation to switch vmstat shepherd to flush
per-CPU counters remotely, use xchg instead of a
pair of read/write instructions.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Index: linux-vmstat-remote/mm/vmstat.c
===================================================================
--- linux-vmstat-remote.orig/mm/vmstat.c
+++ linux-vmstat-remote/mm/vmstat.c
@@ -883,7 +883,7 @@ static int refresh_cpu_vm_stats(void)
}
/*
- * Fold the data for an offline cpu into the global array.
+ * Fold the data for a cpu into the global array.
* There cannot be any access by the offline cpu and therefore
* synchronization is simplified.
*/
@@ -904,8 +904,7 @@ void cpu_vm_stats_fold(int cpu)
if (pzstats->vm_stat_diff[i]) {
int v;
- v = pzstats->vm_stat_diff[i];
- pzstats->vm_stat_diff[i] = 0;
+ v = xchg(&pzstats->vm_stat_diff[i], 0);
atomic_long_add(v, &zone->vm_stat[i]);
global_zone_diff[i] += v;
}
@@ -915,8 +914,7 @@ void cpu_vm_stats_fold(int cpu)
if (pzstats->vm_numa_event[i]) {
unsigned long v;
- v = pzstats->vm_numa_event[i];
- pzstats->vm_numa_event[i] = 0;
+ v = xchg(&pzstats->vm_numa_event[i], 0);
zone_numa_event_add(v, zone, i);
}
}
@@ -932,8 +930,7 @@ void cpu_vm_stats_fold(int cpu)
if (p->vm_node_stat_diff[i]) {
int v;
- v = p->vm_node_stat_diff[i];
- p->vm_node_stat_diff[i] = 0;
+ v = xchg(&p->vm_node_stat_diff[i], 0);
atomic_long_add(v, &pgdat->vm_stat[i]);
global_node_diff[i] += v;
}
next prev parent reply other threads:[~2023-03-05 13:42 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-05 13:36 [PATCH v4 00/12] fold per-CPU vmstats remotely Marcelo Tosatti
2023-03-05 13:36 ` [PATCH v4 01/12] mm/vmstat: remove remote node draining Marcelo Tosatti
2023-03-09 17:11 ` Vlastimil Babka
2023-03-13 16:41 ` Marcelo Tosatti
2023-03-05 13:36 ` [PATCH v4 02/12] this_cpu_cmpxchg: ARM64: switch this_cpu_cmpxchg to locked, add _local function Marcelo Tosatti
2023-03-05 13:37 ` [PATCH v4 03/12] this_cpu_cmpxchg: loongarch: " Marcelo Tosatti
2023-03-05 13:37 ` [PATCH v4 04/12] this_cpu_cmpxchg: S390: " Marcelo Tosatti
2023-03-05 13:37 ` [PATCH v4 05/12] this_cpu_cmpxchg: x86: " Marcelo Tosatti
2023-03-06 11:22 ` Peter Zijlstra
2023-03-08 21:42 ` Marcelo Tosatti
2023-03-05 13:37 ` [PATCH v4 06/12] add this_cpu_cmpxchg_local and asm-generic definitions Marcelo Tosatti
2023-03-05 13:37 ` [PATCH v4 07/12] convert this_cpu_cmpxchg users to this_cpu_cmpxchg_local Marcelo Tosatti
2023-03-05 13:37 ` [PATCH v4 08/12] mm/vmstat: switch counter modification to cmpxchg Marcelo Tosatti
2023-03-05 13:37 ` [PATCH v4 09/12] vmstat: switch per-cpu vmstat counters to 32-bits Marcelo Tosatti
2023-03-05 13:37 ` Marcelo Tosatti [this message]
2023-03-05 13:37 ` [PATCH v4 11/12] mm/vmstat: switch vmstat shepherd to flush per-CPU counters remotely Marcelo Tosatti
2023-03-05 13:37 ` [PATCH v4 12/12] mm/vmstat: refresh stats remotely instead of via work item Marcelo Tosatti
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