[llvm-dev] (Thin)LTO llvm build

Carsten Mattner via llvm-dev
Mon, 26 Sep 2016 15:08:59 -0000

On Mon, Sep 26, 2016 at 4:25 PM, Teresa Johnson <tejohnson at google.com>
wrote:
> No worries, thanks for the update. Teresa

2048 wasn't enough. Bumped to 4096. Only 1300 ninja targets left.

Once I've been successful with this, I might try building a ThinLTO Firefox
or maybe Chromium, although browsers usually have PGO profiles one
can run for feeding back real-world exercise. Not sure if PGO can be
combined with LTO, or if it makes sense at all...

What would be more fun is combining ThinLTO for C code with MLton
for SML code when building Ur/Web.

> On Mon, Sep 26, 2016, 7:16 AM Carsten Mattner <carstenmattner at
gmail.com>
> wrote:
>>
>> On Mon, Sep 26, 2016 at 3:52 PM, Teresa Johnson <tejohnson at
google.com>
>> wrote:
>> >
>> > ThinLTO needs to create as many temporary files as there are input
>> > modules to the link. From your 'ls' below, it doesn't
look like there is
>> > an incredibly huge amount already created, can you check your
limits?
>> > What is the output of:
>> >
>> > $ ulimit -n
>> >
>> > and
>> >
>> > $ sysctl fs.file-max
>>
>> Sorry for the noise, forgot to verify because I had assumed it was
>> still set to 4096 from a similar change a couple days ago.
>> Alas, it's just 1024 in this session. Given the # of object files,
>> 2048 looks more than enough. Going to re-run with that.