From: YiFei Zhu > Sent: 24 September 2020 15:17 > > On Thu, Sep 24, 2020 at 8:47 AM David Laight <David.Laight@xxxxxxxxxx> wrote: > > I doubt the compiler will do what you want. > > Looking at it, in most cases there are one or two entries. > > I think only MIPS has three. > > It does ;) GCC 10.2.0: > > $ objdump -d kernel/seccomp.o | less > [...] > 0000000000001520 <__seccomp_filter>: > [...] > 1587: 41 8b 54 24 04 mov 0x4(%r12),%edx > 158c: b9 08 01 00 00 mov $0x108,%ecx > 1591: 81 fa 3e 00 00 c0 cmp $0xc000003e,%edx > 1597: 75 2e jne 15c7 <__seccomp_filter+0xa7> > [...] > 15c7: 81 fa 03 00 00 40 cmp $0x40000003,%edx > 15cd: b9 40 01 00 00 mov $0x140,%ecx > 15d2: 74 c5 je 1599 <__seccomp_filter+0x79> > 15d4: 0f 0b ud2 > [...] > 0000000000001cb0 <seccomp_cache_prepare>: > [...] > 1cc4: 41 b9 3e 00 00 c0 mov $0xc000003e,%r9d > [...] > 1dba: 41 b9 03 00 00 40 mov $0x40000003,%r9d > [...] > 0000000000002e30 <proc_pid_seccomp_cache>: > [...] > 2e72: ba 3e 00 00 c0 mov $0xc000003e,%edx > [...] > 2eb5: ba 03 00 00 40 mov $0x40000003,%edx > > Granted, I have CC_OPTIMIZE_FOR_PERFORMANCE rather than > CC_OPTIMIZE_FOR_SIZE, but this patch itself is trying to sacrifice > some of the memory for speed. Don't both CC_OPTIMIZE_FOR_PERFORMANCE (-??) and CC_OPTIMIZE_FOR_SIZE (-s) generate terrible code? Try with a slghtly older gcc. I think that entire optimisation (discarding const arrays) is very recent. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales) _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/containers
