From: Duy Nguyen <pclouds@gmail.com>
Date: Sat, 15 Sep 2018 10:24:48 GMT
Subject: Re: [PATCH v5 2/5] read-cache: load cache extensions on a worker thread
Message-ID: <CACsJy8D-sM2SSfTMmsR0uKnP0FM9fGrN0Z-pH5irMsH1=-jrmQ@mail.gmail.com>
In-Reply-To: <CACsJy8ATsS6S5zib2FqJf1stPcGwSTO1qYBSz514Xu2GfJ4Apw@mail.gmail.com>

On Sat, Sep 15, 2018 at 12:22 PM Duy Nguyen <pclouds@gmail.com> wrote:
> > @@ -1944,6 +1993,26 @@ int do_read_index(struct index_state *istate, const char *path, int must_exist)
> >         istate->cache = xcalloc(istate->cache_alloc, sizeof(*istate->cache));
> >         istate->initialized = 1;
> >
> > +       p.istate = istate;
> > +       p.mmap = mmap;
> > +       p.mmap_size = mmap_size;
> > +
> > +#ifndef NO_PTHREADS
> > +       nr_threads = git_config_get_index_threads();
> > +       if (!nr_threads)
> > +               nr_threads = online_cpus();
> > +
> > +       if (nr_threads >= 2) {
> > +               extension_offset = read_eoie_extension(mmap, mmap_size);
> > +               if (extension_offset) {

One more thing I forgot. If the extension area is small enough, then
we should not need to create a thread to parse extensions in parallel.
We should know roughly how much work we need because we know the total
size of all extensions.

> > +                       /* create a thread to load the index extensions */
>
> Pointless comment. It's pretty clear from the pthread_create() below
> thanks to good function naming. Please remove.
>
> > +                       p.src_offset = extension_offset;
> > +                       if (pthread_create(&p.pthread, NULL, load_index_extensions, &p))
> > +                               die(_("unable to create load_index_extensions_thread"));
> > +               }
> > +       }
> > +#endif
> > +
> >         if (istate->version == 4) {
> >                 previous_name = &previous_name_buf;
> >                 mem_pool_init(&istate->ce_mem_pool,
-- 
Duy