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Date:   Mon, 28 Oct 2019 16:39:30 +0100
From:   Jiri Olsa <jolsa@redhat.com>
To:     Adrian Hunter <adrian.hunter@intel.com>
Cc:     Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        "H . Peter Anvin" <hpa@zytor.com>, x86@kernel.org,
        Mark Rutland <mark.rutland@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Mathieu Poirier <mathieu.poirier@linaro.org>,
        Leo Yan <leo.yan@linaro.org>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH RFC 2/6] perf dso: Refactor dso_cache__read()
Message-ID: <20191028153930.GA15449@krava>
References: <20191025130000.13032-1-adrian.hunter@intel.com>
 <20191025130000.13032-3-adrian.hunter@intel.com>
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On Fri, Oct 25, 2019 at 03:59:56PM +0300, Adrian Hunter wrote:

SNIP

> +}
> =20
> -=09return ret;
> +static struct dso_cache *dso_cache__find(struct dso *dso,
> +=09=09=09=09=09 struct machine *machine,
> +=09=09=09=09=09 u64 offset,
> +=09=09=09=09=09 ssize_t *ret)
> +{
> +=09struct dso_cache *cache =3D __dso_cache__find(dso, offset);
> +
> +=09return cache ? cache : dso_cache__populate(dso, machine, offset, ret)=
;
>  }
> =20
>  static ssize_t dso_cache_read(struct dso *dso, struct machine *machine,
>  =09=09=09      u64 offset, u8 *data, ssize_t size)
>  {
>  =09struct dso_cache *cache;
> +=09ssize_t ret =3D 0;
> =20
> -=09cache =3D dso_cache__find(dso, offset);
> -=09if (cache)
> -=09=09return dso_cache__memcpy(cache, offset, data, size);
> -=09else
> -=09=09return dso_cache__read(dso, machine, offset, data, size);
> +=09cache =3D dso_cache__find(dso, machine, offset, &ret);
> +=09if (!cache)
> +=09=09return ret;

why not use the ERR_* macros to get error through the pointer
instead of adding extra argument?

jirka


> +
> +=09return dso_cache__memcpy(cache, offset, data, size);
>  }
> =20
>  /*
> --=20
> 2.17.1
>=20