lkml.org 
[lkml]   [2023]   [Oct]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH v2 3/4] mm/ksm: add tracepoint for ksm advisor
    Date
    This adds a new tracepoint for the ksm advisor. It reports the last scan
    time, the new setting of the pages_to_scan parameter and the average cpu
    percent usage of the ksmd background thread for the last scan.

    Signed-off-by: Stefan Roesch <shr@devkernel.io>
    ---
    include/trace/events/ksm.h | 33 +++++++++++++++++++++++++++++++++
    mm/ksm.c | 1 +
    2 files changed, 34 insertions(+)

    diff --git a/include/trace/events/ksm.h b/include/trace/events/ksm.h
    index b5ac35c1d0e8..e728647b5d26 100644
    --- a/include/trace/events/ksm.h
    +++ b/include/trace/events/ksm.h
    @@ -245,6 +245,39 @@ TRACE_EVENT(ksm_remove_rmap_item,
    __entry->pfn, __entry->rmap_item, __entry->mm)
    );

    +/**
    + * ksm_advisor - called after the advisor has run
    + *
    + * @scan_time: scan time in seconds
    + * @pages_to_scan: new pages_to_scan value
    + * @cpu_percent: cpu usage in percent
    + *
    + * Allows to trace the ksm advisor.
    + */
    +TRACE_EVENT(ksm_advisor,
    +
    + TP_PROTO(s64 scan_time, unsigned long pages_to_scan,
    + unsigned int cpu_percent),
    +
    + TP_ARGS(scan_time, pages_to_scan, cpu_percent),
    +
    + TP_STRUCT__entry(
    + __field(s64, scan_time)
    + __field(unsigned long, pages_to_scan)
    + __field(unsigned int, cpu_percent)
    + ),
    +
    + TP_fast_assign(
    + __entry->scan_time = scan_time;
    + __entry->pages_to_scan = pages_to_scan;
    + __entry->cpu_percent = cpu_percent;
    + ),
    +
    + TP_printk("ksm scan time %lld pages_to_scan %lu cpu percent %u",
    + __entry->scan_time, __entry->pages_to_scan,
    + __entry->cpu_percent)
    +);
    +
    #endif /* _TRACE_KSM_H */

    /* This part must be outside protection */
    diff --git a/mm/ksm.c b/mm/ksm.c
    index 042ecaeb0beb..b2a519083d66 100644
    --- a/mm/ksm.c
    +++ b/mm/ksm.c
    @@ -442,6 +442,7 @@ static void scan_time_advisor(unsigned long scan_time)
    advisor_ctx.cpu_time = cpu_time;

    ksm_thread_pages_to_scan = pages;
    + trace_ksm_advisor(scan_time, pages, cpu_percent);
    }

    static void run_advisor(void)
    --
    2.39.3
    \
     
     \ /
      Last update: 2023-10-28 02:14    [W:7.267 / U:0.412 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site