lkml.org 
[lkml]   [2022]   [Jun]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH v5 21/21] x86/resctrl: Make resctrl_arch_rmid_read() return values in bytes
    Date
    resctrl_arch_rmid_read() returns a value in chunks, as read from the
    hardware. This needs scaling to bytes by mon_scale, as provided by
    the architecture code.

    Now that resctrl_arch_rmid_read() performs the overflow and corrections
    itself, it may as well return a value in bytes directly. This allows
    the accesses to the architecture specific 'hw' structure to be removed.

    Move the mon_scale conversion into resctrl_arch_rmid_read().
    mbm_bw_count() is updated to calculate bandwidth from bytes.

    Reviewed-by: Jamie Iles <quic_jiles@quicinc.com>
    Tested-by: Xin Hao <xhao@linux.alibaba.com>
    Reviewed-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
    Tested-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
    Tested-by: Cristian Marussi <cristian.marussi@arm.com>
    Signed-off-by: James Morse <james.morse@arm.com>
    ---
    Changes since v3:
    * Only set val in one place in restrl_arch_rmid_read()
    * Use SZ_1M to improve readability
    ---
    arch/x86/kernel/cpu/resctrl/ctrlmondata.c | 6 ++----
    arch/x86/kernel/cpu/resctrl/internal.h | 4 ++--
    arch/x86/kernel/cpu/resctrl/monitor.c | 24 +++++++++++------------
    include/linux/resctrl.h | 2 +-
    4 files changed, 16 insertions(+), 20 deletions(-)

    diff --git a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
    index d3f7eb2ac14b..03fc91d8bc9f 100644
    --- a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
    +++ b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
    @@ -549,7 +549,6 @@ void mon_event_read(struct rmid_read *rr, struct rdt_resource *r,
    int rdtgroup_mondata_show(struct seq_file *m, void *arg)
    {
    struct kernfs_open_file *of = m->private;
    - struct rdt_hw_resource *hw_res;
    u32 resid, evtid, domid;
    struct rdtgroup *rdtgrp;
    struct rdt_resource *r;
    @@ -569,8 +568,7 @@ int rdtgroup_mondata_show(struct seq_file *m, void *arg)
    domid = md.u.domid;
    evtid = md.u.evtid;

    - hw_res = &rdt_resources_all[resid];
    - r = &hw_res->r_resctrl;
    + r = &rdt_resources_all[resid].r_resctrl;
    d = rdt_find_domain(r, domid, NULL);
    if (IS_ERR_OR_NULL(d)) {
    ret = -ENOENT;
    @@ -584,7 +582,7 @@ int rdtgroup_mondata_show(struct seq_file *m, void *arg)
    else if (rr.err == -EINVAL)
    seq_puts(m, "Unavailable\n");
    else
    - seq_printf(m, "%llu\n", rr.val * hw_res->mon_scale);
    + seq_printf(m, "%llu\n", rr.val);

    out:
    rdtgroup_kn_unlock(of->kn);
    diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
    index c05e9b7cf77a..5f7128686cfd 100644
    --- a/arch/x86/kernel/cpu/resctrl/internal.h
    +++ b/arch/x86/kernel/cpu/resctrl/internal.h
    @@ -279,13 +279,13 @@ struct rftype {

    /**
    * struct mbm_state - status for each MBM counter in each domain
    - * @prev_bw_chunks: Previous chunks value read for bandwidth calculation
    + * @prev_bw_bytes: Previous bytes value read for bandwidth calculation
    * @prev_bw: The most recent bandwidth in MBps
    * @delta_bw: Difference between the current and previous bandwidth
    * @delta_comp: Indicates whether to compute the delta_bw
    */
    struct mbm_state {
    - u64 prev_bw_chunks;
    + u64 prev_bw_bytes;
    u32 prev_bw;
    u32 delta_bw;
    bool delta_comp;
    diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c
    index 8d15568d7121..efe0c30d3a12 100644
    --- a/arch/x86/kernel/cpu/resctrl/monitor.c
    +++ b/arch/x86/kernel/cpu/resctrl/monitor.c
    @@ -16,6 +16,7 @@
    */

    #include <linux/module.h>
    +#include <linux/sizes.h>
    #include <linux/slab.h>

    #include <asm/cpu_device_id.h>
    @@ -189,7 +190,7 @@ int resctrl_arch_rmid_read(struct rdt_resource *r, struct rdt_domain *d,
    struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
    struct rdt_hw_domain *hw_dom = resctrl_to_arch_dom(d);
    struct arch_mbm_state *am;
    - u64 msr_val;
    + u64 msr_val, chunks;

    if (!cpumask_test_cpu(smp_processor_id(), &d->cpu_mask))
    return -EINVAL;
    @@ -214,12 +215,14 @@ int resctrl_arch_rmid_read(struct rdt_resource *r, struct rdt_domain *d,
    if (am) {
    am->chunks += mbm_overflow_count(am->prev_msr, msr_val,
    hw_res->mbm_width);
    - *val = get_corrected_mbm_count(rmid, am->chunks);
    + chunks = get_corrected_mbm_count(rmid, am->chunks);
    am->prev_msr = msr_val;
    } else {
    - *val = msr_val;
    + chunks = msr_val;
    }

    + *val = chunks * hw_res->mon_scale;
    +
    return 0;
    }

    @@ -232,7 +235,6 @@ int resctrl_arch_rmid_read(struct rdt_resource *r, struct rdt_domain *d,
    void __check_limbo(struct rdt_domain *d, bool force_free)
    {
    struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl;
    - struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
    struct rmid_entry *entry;
    u32 crmid = 1, nrmid;
    bool rmid_dirty;
    @@ -255,7 +257,6 @@ void __check_limbo(struct rdt_domain *d, bool force_free)
    QOS_L3_OCCUP_EVENT_ID, &val)) {
    rmid_dirty = true;
    } else {
    - val *= hw_res->mon_scale;
    rmid_dirty = (val >= resctrl_rmid_realloc_threshold);
    }

    @@ -299,7 +300,6 @@ int alloc_rmid(void)
    static void add_rmid_to_limbo(struct rmid_entry *entry)
    {
    struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl;
    - struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
    struct rdt_domain *d;
    int cpu, err;
    u64 val = 0;
    @@ -311,7 +311,6 @@ static void add_rmid_to_limbo(struct rmid_entry *entry)
    err = resctrl_arch_rmid_read(r, d, entry->rmid,
    QOS_L3_OCCUP_EVENT_ID,
    &val);
    - val *= hw_res->mon_scale;
    if (err || val <= resctrl_rmid_realloc_threshold)
    continue;
    }
    @@ -403,15 +402,14 @@ static int __mon_event_count(u32 rmid, struct rmid_read *rr)
    */
    static void mbm_bw_count(u32 rmid, struct rmid_read *rr)
    {
    - struct rdt_hw_resource *hw_res = resctrl_to_arch_res(rr->r);
    struct mbm_state *m = &rr->d->mbm_local[rmid];
    - u64 cur_bw, chunks, cur_chunks;
    + u64 cur_bw, bytes, cur_bytes;

    - cur_chunks = rr->val;
    - chunks = cur_chunks - m->prev_bw_chunks;
    - m->prev_bw_chunks = cur_chunks;
    + cur_bytes = rr->val;
    + bytes = cur_bytes - m->prev_bw_bytes;
    + m->prev_bw_bytes = cur_bytes;

    - cur_bw = (chunks * hw_res->mon_scale) >> 20;
    + cur_bw = bytes / SZ_1M;

    if (m->delta_comp)
    m->delta_bw = abs(cur_bw - m->prev_bw);
    diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h
    index cb857f753322..0cf5b20c6ddf 100644
    --- a/include/linux/resctrl.h
    +++ b/include/linux/resctrl.h
    @@ -227,7 +227,7 @@ void resctrl_offline_domain(struct rdt_resource *r, struct rdt_domain *d);
    * @d: domain that the counter should be read from.
    * @rmid: rmid of the counter to read.
    * @eventid: eventid to read, e.g. L3 occupancy.
    - * @val: result of the counter read in chunks.
    + * @val: result of the counter read in bytes.
    *
    * Call from process context on a CPU that belongs to domain @d.
    *
    --
    2.30.2
    \
     
     \ /
      Last update: 2022-06-22 18:50    [W:4.048 / U:0.224 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site