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From: Jiri Olsa <jolsa@redhat.com>
To: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: "Jiri Olsa" <jolsa@kernel.org>,
	"Alexei Starovoitov" <ast@kernel.org>,
	"Daniel Borkmann" <daniel@iogearbox.net>,
	Networking <netdev@vger.kernel.org>, bpf <bpf@vger.kernel.org>,
	"Andrii Nakryiko" <andriin@fb.com>, "Yonghong Song" <yhs@fb.com>,
	"Song Liu" <songliubraving@fb.com>,
	"Martin KaFai Lau" <kafai@fb.com>,
	"Jakub Kicinski" <kuba@kernel.org>,
	"David Miller" <davem@redhat.com>,
	"Björn Töpel" <bjorn.topel@intel.com>,
	"John Fastabend" <john.fastabend@gmail.com>,
	"Jesper Dangaard Brouer" <hawk@kernel.org>
Subject: Re: [PATCH 06/14] bpf: Add bpf_kallsyms_tree tree
Date: Wed, 12 Feb 2020 11:49:37 +0100
Message-ID: <20200212104937.GC183981@krava> (raw)
In-Reply-To: <CAEf4BzYyJBh+zh0NYTEXV=ocCCtJJ_+skeRJQJt1AKQSAEEWqw@mail.gmail.com>

On Tue, Feb 11, 2020 at 10:21:10AM -0800, Andrii Nakryiko wrote:
> On Sat, Feb 8, 2020 at 7:43 AM Jiri Olsa <jolsa@kernel.org> wrote:
> >
> > The bpf_tree is used both for kallsyms iterations and searching
> > for exception tables of bpf programs, which is needed only for
> > bpf programs.
> >
> > Adding bpf_kallsyms_tree that will hold symbols for all bpf_prog,
> > bpf_trampoline and bpf_dispatcher objects and keeping bpf_tree
> > only for bpf_prog objects exception tables search to keep it fast.
> >
> > Signed-off-by: Jiri Olsa <jolsa@kernel.org>
> > ---
> >  include/linux/bpf.h |  1 +
> >  kernel/bpf/core.c   | 60 ++++++++++++++++++++++++++++++++++++++++-----
> >  2 files changed, 55 insertions(+), 6 deletions(-)
> >
> > diff --git a/include/linux/bpf.h b/include/linux/bpf.h
> > index da67ca3afa2f..151d7b1c8435 100644
> > --- a/include/linux/bpf.h
> > +++ b/include/linux/bpf.h
> > @@ -468,6 +468,7 @@ struct bpf_ksym {
> >         unsigned long            end;
> >         char                     name[KSYM_NAME_LEN];
> >         struct list_head         lnode;
> > +       struct latch_tree_node   tnode;
> >  };
> >
> >  enum bpf_tramp_prog_type {
> > diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
> > index b9b7077e60f3..1daa72341450 100644
> > --- a/kernel/bpf/core.c
> > +++ b/kernel/bpf/core.c
> > @@ -606,8 +606,46 @@ static const struct latch_tree_ops bpf_tree_ops = {
> >         .comp   = bpf_tree_comp,
> >  };
> >
> > +static __always_inline unsigned long
> > +bpf_get_ksym_start(struct latch_tree_node *n)
> 
> I thought static functions are never marked as inline in kernel
> sources. Are there some special cases when its ok/necessary?

I followed the other latch tree ops functions and did not think
much about that.. will check

> 
> > +{
> > +       const struct bpf_ksym *ksym;
> > +
> > +       ksym = container_of(n, struct bpf_ksym, tnode);
> > +       return ksym->start;
> > +}
> > +
> > +static __always_inline bool
> > +bpf_ksym_tree_less(struct latch_tree_node *a,
> > +                  struct latch_tree_node *b)
> > +{
> > +       return bpf_get_ksym_start(a) < bpf_get_ksym_start(b);
> > +}
> > +
> > +static __always_inline int
> > +bpf_ksym_tree_comp(void *key, struct latch_tree_node *n)
> > +{
> > +       unsigned long val = (unsigned long)key;
> > +       const struct bpf_ksym *ksym;
> > +
> > +       ksym = container_of(n, struct bpf_ksym, tnode);
> > +
> > +       if (val < ksym->start)
> > +               return -1;
> > +       if (val >= ksym->end)
> > +               return  1;
> > +
> > +       return 0;
> > +}
> > +
> > +static const struct latch_tree_ops bpf_kallsyms_tree_ops = {
> 
> Given all the helper functions use bpf_ksym_tree and bpf_ksym
> (bpf_ksym_find) prefixes, call this bpf_ksym_tree_ops?

right, should be bpf_ksym_tree_ops as you said

> 
> > +       .less   = bpf_ksym_tree_less,
> > +       .comp   = bpf_ksym_tree_comp,
> > +};
> > +
> >  static DEFINE_SPINLOCK(bpf_lock);
> >  static LIST_HEAD(bpf_kallsyms);
> > +static struct latch_tree_root bpf_kallsyms_tree __cacheline_aligned;
> 
> same as above, bpf_ksym_tree for consistency?

right, thanks

jirka


  reply index

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-08 15:41 [PATCH 00/14] bpf: Add trampoline and dispatcher to /proc/kallsyms Jiri Olsa
2020-02-08 15:41 ` [PATCH 01/14] x86/mm: Rename is_kernel_text to __is_kernel_text Jiri Olsa
2020-02-08 15:41 ` [PATCH 02/14] bpf: Add bpf_trampoline_ name prefix for DECLARE_BPF_DISPATCHER Jiri Olsa
2020-02-08 15:41 ` [PATCH 03/14] bpf: Add struct bpf_ksym Jiri Olsa
2020-02-08 15:41 ` [PATCH 04/14] bpf: Add name to " Jiri Olsa
2020-02-08 15:42 ` [PATCH 05/14] bpf: Add lnode list node " Jiri Olsa
2020-02-08 15:42 ` [PATCH 06/14] bpf: Add bpf_kallsyms_tree tree Jiri Olsa
2020-02-11 18:21   ` Andrii Nakryiko
2020-02-12 10:49     ` Jiri Olsa [this message]
2020-02-08 15:42 ` [PATCH 07/14] bpf: Move bpf_tree add/del from bpf_prog_ksym_node_add/del Jiri Olsa
2020-02-08 15:42 ` [PATCH 08/14] bpf: Separate kallsyms add/del functions Jiri Olsa
2020-02-08 15:42 ` [PATCH 09/14] bpf: Add bpf_ksym_add/del functions Jiri Olsa
2020-02-08 15:42 ` [PATCH 10/14] bpf: Re-initialize lnode in bpf_ksym_del Jiri Olsa
2020-02-11 18:28   ` Andrii Nakryiko
2020-02-12 10:43     ` Jiri Olsa
2020-02-08 15:42 ` [PATCH 11/14] bpf: Rename bpf_tree to bpf_progs_tree Jiri Olsa
2020-02-08 15:42 ` [PATCH 12/14] bpf: Add trampolines to kallsyms Jiri Olsa
2020-02-11 18:51   ` Andrii Nakryiko
2020-02-12 11:10     ` Jiri Olsa
2020-02-12 16:33       ` Andrii Nakryiko
2020-02-12 22:58         ` Jiri Olsa
2020-02-12 23:02         ` Jiri Olsa
2020-02-08 15:42 ` [PATCH 13/14] bpf: Add dispatchers " Jiri Olsa
2020-02-11 19:03   ` Andrii Nakryiko
2020-02-12 10:52     ` Jiri Olsa
2020-02-08 15:42 ` [PATCH 14/14] bpf: Sort bpf kallsyms symbols Jiri Olsa
2020-02-11 19:12   ` Andrii Nakryiko
2020-02-10 15:51 ` [PATCH 00/14] bpf: Add trampoline and dispatcher to /proc/kallsyms Björn Töpel
2020-02-10 16:17   ` Jiri Olsa
2020-02-11 19:32     ` Arnaldo Carvalho de Melo
2020-02-12 11:13       ` Jiri Olsa
2020-02-12 13:31         ` Arnaldo Carvalho de Melo
2020-02-12 22:40           ` Jiri Olsa
2020-02-13 16:23   ` Jiri Olsa
2020-02-11 19:13 ` Arnaldo Carvalho de Melo
2020-02-12 10:46   ` Jiri Olsa

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