Re: Ccache prefetch
Ian Albany <[email protected]>
| Newsgroups | gmane.comp.compilers.ccache |
|---|---|
| Message-ID | <[email protected]> |
Hi I guest you missed my point. I believe that the discrepancy between "memory" caches and "disk" caches on a typical harvard architecture these days is such that I derive great benefits by reading the later into the former via another thread on the same build machine. I do derive a measure of improvement, but not as great as I derive from subsequent builds after a reboot than I do after the former. So my point is, I guess, is there any way to ccache to know the locality of hits for a given object and therefore preload those objects which would entail a separate thread of execution. I know this adds some complexity but in effect, I would say that when I build the kernel, I am usually hitting the cache in a normally pretty predetermined order. Yes but running everything in tmpfs on a 32GB system everything does fly. Alby 11.05.2014, 15:51, "Eitan Adler" <[email protected]>: > On 10 May 2014 22:11, Ian Albany <[email protected]> wrote: > >> Hi >> >> I have what prima facie appears to be a bit of a silly question about ccache. But first, let me just say that I have been uging ccache for over a decade and I am quite happy overall. >> >> However, during many compiltaions I notice that the build time on linux at least varies and I have pinned it down to the fact that most of the blocking withing ccache with my current setup occurs with disk IO. > > I can not speak to Linux but have you tried putting the cache on a > tmpfs or mdfs partition? In addition do you find that existing disk > caching does not help you? > > -- > Eitan Adler _______________________________________________ ccache mailing list [email protected] https://lists.samba.org/mailman/listinfo/ccache