From dac509311fb3744fa899f2cc6b2fd40c84100bbf Mon Sep 17 00:00:00 2001 From: Andriy Gapon Date: Fri, 23 Jul 2010 16:46:42 +0000 Subject: [PATCH] cpufreq: allocate long-lived buffer for handling of sysctl requests At present the cpufreq sysctl handler for current level setting would allocate and deallocate a temporary buffer of 24KB even to handle a read-only query. This puts unnecessary load on memory subsystem when current level is checked frequently, e.g. when the likes of powerd and system monitoring software are running. Change the strategy to allocating a long-lived buffer for handling the requests. Reviewed by: njl MFC after: 2 weeks --- sys/kern/kern_cpu.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/sys/kern/kern_cpu.c b/sys/kern/kern_cpu.c index 4c4f961931f..3429a0f5266 100644 --- a/sys/kern/kern_cpu.c +++ b/sys/kern/kern_cpu.c @@ -76,6 +76,7 @@ struct cpufreq_softc { device_t dev; struct sysctl_ctx_list sysctl_ctx; struct task startup_task; + struct cf_level *levels_buf; }; struct cf_setting_array { @@ -180,6 +181,8 @@ cpufreq_attach(device_t dev) CF_DEBUG("initializing one-time data for %s\n", device_get_nameunit(dev)); + sc->levels_buf = malloc(CF_MAX_LEVELS * sizeof(*sc->levels_buf), + M_DEVBUF, M_WAITOK); SYSCTL_ADD_PROC(&sc->sysctl_ctx, SYSCTL_CHILDREN(device_get_sysctl_tree(parent)), OID_AUTO, "freq", CTLTYPE_INT | CTLFLAG_RW, sc, 0, @@ -227,6 +230,7 @@ cpufreq_detach(device_t dev) numdevs = devclass_get_count(cpufreq_dc); if (numdevs == 1) { CF_DEBUG("final shutdown for %s\n", device_get_nameunit(dev)); + free(sc->levels_buf, M_DEVBUF); } return (0); @@ -870,9 +874,7 @@ cpufreq_curr_sysctl(SYSCTL_HANDLER_ARGS) devs = NULL; sc = oidp->oid_arg1; - levels = malloc(CF_MAX_LEVELS * sizeof(*levels), M_TEMP, M_NOWAIT); - if (levels == NULL) - return (ENOMEM); + levels = sc->levels_buf; error = CPUFREQ_GET(sc->dev, &levels[0]); if (error) @@ -915,8 +917,6 @@ cpufreq_curr_sysctl(SYSCTL_HANDLER_ARGS) out: if (devs) free(devs, M_TEMP); - if (levels) - free(levels, M_TEMP); return (error); } @@ -934,7 +934,7 @@ cpufreq_levels_sysctl(SYSCTL_HANDLER_ARGS) /* Get settings from the device and generate the output string. */ count = CF_MAX_LEVELS; - levels = malloc(count * sizeof(*levels), M_TEMP, M_NOWAIT); + levels = sc->levels_buf; if (levels == NULL) { sbuf_delete(&sb); return (ENOMEM); @@ -957,7 +957,6 @@ cpufreq_levels_sysctl(SYSCTL_HANDLER_ARGS) error = sysctl_handle_string(oidp, sbuf_data(&sb), sbuf_len(&sb), req); out: - free(levels, M_TEMP); sbuf_delete(&sb); return (error); }