From: Thomas Monjalon <thomas@monjalon.net>
To: fengchengwen <fengchengwen@huawei.com>
Cc: mb@smartsharesystems.com, Kevin Laatz <kevin.laatz@intel.com>,
Bruce Richardson <bruce.richardson@intel.com>,
dev@dpdk.org, david.marchand@redhat.com
Subject: Re: [PATCH v4] dmadev: add tracepoints
Date: Mon, 10 Jul 2023 08:49:38 +0200 [thread overview]
Message-ID: <7265847.4vTCxPXJkl@thomas> (raw)
In-Reply-To: <1f0b8df9-6a38-57e1-0d9e-ce031297f191@huawei.com>
09/07/2023 05:23, fengchengwen:
> Hi Thomas,
>
> On 2023/7/7 18:40, Thomas Monjalon wrote:
> > 26/05/2023 10:42, Chengwen Feng:
> >> Add tracepoints at important APIs for tracing support.
> >>
> >> Signed-off-by: Chengwen Feng <fengchengwen@huawei.com>
> >> Acked-by: Morten Brørup <mb@smartsharesystems.com>
> >>
> >> ---
> >> v4: Fix asan smoke fail.
> >> v3: Address Morten's comment:
> >> Move stats_get and vchan_status and to trace_fp.h.
> >> v2: Address Morten's comment:
> >> Make stats_get as fast-path trace-points.
> >> Place fast-path trace-point functions behind in version.map.
> >
> > There are more things to fix.
> > First you must export rte_dmadev_trace_fp.h as it is included by rte_dmadev.h.
>
> It was already included by rte_dmadev.h:
> diff --git a/lib/dmadev/rte_dmadev.h b/lib/dmadev/rte_dmadev.h
> index e61d71959e..e792b90ef8 100644
> --- a/lib/dmadev/rte_dmadev.h
> +++ b/lib/dmadev/rte_dmadev.h
> @@ -796,6 +796,7 @@ struct rte_dma_sge {
> };
>
> #include "rte_dmadev_core.h"
> +#include "rte_dmadev_trace_fp.h"
>
>
> > Note: you could have caught this if testing the example app for DMA.
> > Second, you must avoid structs and enum in this header file,
>
> Let me explain the #if #endif logic:
>
> For the function:
> uint16_t
> rte_dma_completed(int16_t dev_id, uint16_t vchan, const uint16_t nb_cpls,
> uint16_t *last_idx, bool *has_error)
>
> The common trace implementation:
> RTE_TRACE_POINT_FP(
> rte_dma_trace_completed,
> RTE_TRACE_POINT_ARGS(int16_t dev_id, uint16_t vchan,
> const uint16_t nb_cpls, uint16_t *last_idx,
> bool *has_error, uint16_t ret),
> rte_trace_point_emit_i16(dev_id);
> rte_trace_point_emit_u16(vchan);
> rte_trace_point_emit_u16(nb_cpls);
> rte_trace_point_emit_ptr(idx_val);
> rte_trace_point_emit_ptr(has_error);
> rte_trace_point_emit_u16(ret);
> )
>
> But it has a problem: for pointer parameter (e.g. last_idx and has_error), only record
> the pointer value (i.e. address value).
>
> I think the pointer value has no mean (in particular, many of there pointers are stack
> variables), the value of the pointer point to is meaningful.
>
> So I add the pointer reference like below (as V3 did):
> RTE_TRACE_POINT_FP(
> rte_dma_trace_completed,
> RTE_TRACE_POINT_ARGS(int16_t dev_id, uint16_t vchan,
> const uint16_t nb_cpls, uint16_t *last_idx,
> bool *has_error, uint16_t ret),
> int has_error_val = *has_error; // pointer reference
> int last_idx_val = *last_idx; // pointer reference
> rte_trace_point_emit_i16(dev_id);
> rte_trace_point_emit_u16(vchan);
> rte_trace_point_emit_u16(nb_cpls);
> rte_trace_point_emit_int(last_idx_val); // record the value of pointer
> rte_trace_point_emit_int(has_error_val); // record the value of pointer
> rte_trace_point_emit_u16(ret);
> )
>
> Unfortunately, the above lead to asan failed. because in:
> RTE_TRACE_POINT_REGISTER(rte_dma_trace_completed,
> lib.dmadev.completed)
> it will invoke rte_dma_trace_completed() with the parameter is undefined.
>
>
> To solve this problem, consider the rte_dmadev_trace_points.c will include rte_trace_point_register.h,
> and the rte_trace_point_register.h will defined macro: _RTE_TRACE_POINT_REGISTER_H_.
>
> so we update trace points as (as V4 did):
> RTE_TRACE_POINT_FP(
> rte_dma_trace_completed,
> RTE_TRACE_POINT_ARGS(int16_t dev_id, uint16_t vchan,
> const uint16_t nb_cpls, uint16_t *last_idx,
> bool *has_error, uint16_t ret),
> #ifdef _RTE_TRACE_POINT_REGISTER_H_
> uint16_t __last_idx = 0;
> bool __has_error = false;
> last_idx = &__last_idx; // make sure the pointer has meaningful value.
> has_error = &__has_error; // so that the next pointer reference will work well.
> #endif /* _RTE_TRACE_POINT_REGISTER_H_ */
> int has_error_val = *has_error;
> int last_idx_val = *last_idx;
> rte_trace_point_emit_i16(dev_id);
> rte_trace_point_emit_u16(vchan);
> rte_trace_point_emit_u16(nb_cpls);
> rte_trace_point_emit_int(last_idx_val);
> rte_trace_point_emit_int(has_error_val);
> rte_trace_point_emit_u16(ret);
> )
>
> > otherwise it cannot be included alone.
> > Look at what is done in other *_trace_fp.h files.
> >
> >
>
> Whether enable_trace_fp is true or false, the v4 work well.
> Below is that run examples with enable_trace_fp=true.
>
> ./dpdk-test --file-prefix=feng123 --trace=lib.dmadev.* -l 10-11
This is the test application, not the example.
Please make sure examples/dma/ is compiling.
Also, the test chkincs must run fine.
next prev parent reply other threads:[~2023-07-10 6:49 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-12 2:48 [PATCH] " Chengwen Feng
2023-04-12 9:52 ` Bruce Richardson
2023-04-13 3:44 ` fengchengwen
2023-04-13 8:45 ` Bruce Richardson
2023-04-12 11:00 ` Morten Brørup
2023-04-13 6:30 ` fengchengwen
2023-04-13 8:25 ` Morten Brørup
2023-04-15 0:33 ` [PATCH v3] " Chengwen Feng
2023-05-24 21:12 ` Thomas Monjalon
2023-05-27 0:17 ` fengchengwen
2023-05-26 8:42 ` [PATCH v4] " Chengwen Feng
2023-07-03 3:54 ` fengchengwen
2023-07-07 10:40 ` Thomas Monjalon
2023-07-09 3:23 ` fengchengwen
2023-07-10 6:49 ` Thomas Monjalon [this message]
2023-07-10 7:50 ` fengchengwen
2023-07-31 12:48 ` Thomas Monjalon
2023-08-03 7:52 ` fengchengwen
2023-08-14 14:16 ` Thomas Monjalon
2023-10-11 9:55 ` fengchengwen
2023-11-06 20:59 ` Thomas Monjalon
2023-11-07 1:26 ` fengchengwen
2024-01-12 10:38 ` fengchengwen
2023-10-20 2:21 ` [PATCH] dmadev: add tracepoints at control path APIs Chengwen Feng
2023-11-06 20:55 ` Thomas Monjalon
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