lkml.org 
[lkml]   [2020]   [Nov]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH v7 17/22] perf arm-spe: Remove size condition checking for events
    Date
    In the Armv8 ARM (ARM DDI 0487F.c), chapter "D10.2.6 Events packet", it
    describes the event bit is valid with specific payload requirement. For
    example, the Last Level cache access event, the bit is defined as:

    E[8], byte 1 bit [0], when SZ == 0b01 , when SZ == 0b10 ,
    or when SZ == 0b11

    It requires the payload size is at least 2 bytes, when byte 1 (start
    counting from 0) is valid, E[8] (bit 0 in byte 1) can be used for LLC
    access event type. For safety, the code checks the condition for
    payload size firstly, if meet the requirement for payload size, then
    continue to parse event type.

    If review function arm_spe_get_payload(), it has used cast, so any bytes
    beyond the valid size have been set to zeros.

    For this reason, we don't need to check payload size anymore afterwards
    when parse events, thus this patch removes payload size conditions.

    Suggested-by: Andre Przywara <andre.przywara@arm.com>
    Signed-off-by: Leo Yan <leo.yan@linaro.org>
    Reviewed-by: Andre Przywara <andre.przywara@arm.com>
    ---
    tools/perf/util/arm-spe-decoder/arm-spe-decoder.c | 9 +++------
    .../util/arm-spe-decoder/arm-spe-pkt-decoder.c | 14 ++++++--------
    2 files changed, 9 insertions(+), 14 deletions(-)

    diff --git a/tools/perf/util/arm-spe-decoder/arm-spe-decoder.c b/tools/perf/util/arm-spe-decoder/arm-spe-decoder.c
    index cac2ef79c025..90d575cee1b9 100644
    --- a/tools/perf/util/arm-spe-decoder/arm-spe-decoder.c
    +++ b/tools/perf/util/arm-spe-decoder/arm-spe-decoder.c
    @@ -192,16 +192,13 @@ static int arm_spe_read_record(struct arm_spe_decoder *decoder)
    if (payload & BIT(EV_TLB_ACCESS))
    decoder->record.type |= ARM_SPE_TLB_ACCESS;

    - if ((idx == 2 || idx == 4 || idx == 8) &&
    - (payload & BIT(EV_LLC_MISS)))
    + if (payload & BIT(EV_LLC_MISS))
    decoder->record.type |= ARM_SPE_LLC_MISS;

    - if ((idx == 2 || idx == 4 || idx == 8) &&
    - (payload & BIT(EV_LLC_ACCESS)))
    + if (payload & BIT(EV_LLC_ACCESS))
    decoder->record.type |= ARM_SPE_LLC_ACCESS;

    - if ((idx == 2 || idx == 4 || idx == 8) &&
    - (payload & BIT(EV_REMOTE_ACCESS)))
    + if (payload & BIT(EV_REMOTE_ACCESS))
    decoder->record.type |= ARM_SPE_REMOTE_ACCESS;

    if (payload & BIT(EV_MISPRED))
    diff --git a/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c b/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c
    index 6df3f18d1a5f..87ef8866221e 100644
    --- a/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c
    +++ b/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c
    @@ -311,14 +311,12 @@ static int arm_spe_pkt_desc_event(const struct arm_spe_pkt *packet,
    arm_spe_pkt_snprintf(&err, &buf, &buf_len, " NOT-TAKEN");
    if (payload & BIT(EV_MISPRED))
    arm_spe_pkt_snprintf(&err, &buf, &buf_len, " MISPRED");
    - if (packet->index > 1) {
    - if (payload & BIT(EV_LLC_ACCESS))
    - arm_spe_pkt_snprintf(&err, &buf, &buf_len, " LLC-ACCESS");
    - if (payload & BIT(EV_LLC_MISS))
    - arm_spe_pkt_snprintf(&err, &buf, &buf_len, " LLC-REFILL");
    - if (payload & BIT(EV_REMOTE_ACCESS))
    - arm_spe_pkt_snprintf(&err, &buf, &buf_len, " REMOTE-ACCESS");
    - }
    + if (payload & BIT(EV_LLC_ACCESS))
    + arm_spe_pkt_snprintf(&err, &buf, &buf_len, " LLC-ACCESS");
    + if (payload & BIT(EV_LLC_MISS))
    + arm_spe_pkt_snprintf(&err, &buf, &buf_len, " LLC-REFILL");
    + if (payload & BIT(EV_REMOTE_ACCESS))
    + arm_spe_pkt_snprintf(&err, &buf, &buf_len, " REMOTE-ACCESS");

    return err;
    }
    --
    2.17.1
    \
     
     \ /
      Last update: 2020-11-06 02:44    [W:4.214 / U:0.180 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site