Messages in this thread | | | Date | Mon, 24 Apr 2017 18:40:28 +0200 | From | Ingo Molnar <> | Subject | Re: [PATCH v3 07/29] x86: bpf_jit, use ENTRY+ENDPROC |
| |
* Jiri Slaby <jslaby@suse.cz> wrote:
> On 04/24/2017, 05:55 PM, Ingo Molnar wrote: > > * Jiri Slaby <jslaby@suse.cz> wrote: > > > >> On 04/24/2017, 05:08 PM, David Miller wrote: > >>> If you align the entry points, then the code sequence as a whole is > >>> are no longer densely packed. > >> > >> Sure. > >> > >>> Or do I misunderstand how your macros work? > >> > >> Perhaps. So the suggested macros for the code are: > >> #define BPF_FUNC_START_LOCAL(name) \ > >> SYM_START(name, SYM_V_LOCAL, SYM_A_NONE) > >> #define BPF_FUNC_START(name) \ > >> SYM_START(name, SYM_V_GLOBAL, SYM_A_NONE) > >> > >> and they differ from the standard ones: > >> #define SYM_FUNC_START_LOCAL(name) \ > >> SYM_START(name, SYM_V_LOCAL, SYM_A_ALIGN) > >> #define SYM_FUNC_START(name) \ > >> SYM_START(name, SYM_V_GLOBAL, SYM_A_ALIGN) > >> > >> > >> The difference is SYM_A_NONE vs. SYM_A_ALIGN, which means: > >> #define SYM_A_ALIGN ALIGN > >> #define SYM_A_NONE /* nothing */ > >> > >> Does it look OK now? > > > > No, the patch changes alignment which is undesirable, it needs to preserve the > > existing (non-)alignment of the symbols! > > OK, so I am not expressing myself explicitly enough, it seems. > > So, correct, the patch v3 adds alignments. I suggested in the discussion > the macros above. They do not add alignments. If everybody is OK with > that, v4 of the patch won't add alignments. OK?
Yes.
Thanks,
Ingo
| |