On Tue, Mar 10, 2020 at 3:49 PM Ferruh Yigit <ferruh.yi...@intel.com> wrote: > > On 3/6/2020 2:48 PM, David Marchand wrote: > > Since 18.05 and the memory subsystem rework, EAL reserves some big > > (unused) mappings. > > > > In testpmd, we have been locking all pages to avoid page faults during > > benchmark/performance regression tests [1]. > > However, asking for locking all the pages triggers issues on FreeBSD [2] > > and becomes really heavy in some Linux configurations (see [3], [4]). > > > > This patch changes the behavior so that testpmd only lock pages > > containing .text by default. > > > > 1: https://git.dpdk.org/dpdk/commit/?id=1c036b16c284 > > 2: https://git.dpdk.org/dpdk/commit/?id=fb7b8b32cd95 > > 3: https://bugzilla.redhat.com/show_bug.cgi?id=1786923 > > 4: http://mails.dpdk.org/archives/dev/2020-February/158477.html > > > > Signed-off-by: David Marchand <david.march...@redhat.com> > > <...> > > > @@ -3455,6 +3456,42 @@ signal_handler(int signum) > > } > > } > > > > +static void > > +lock_pages(const void *_addr, size_t _len, const char *prefix) > > +{ > > + const void *addr; > > + size_t pagesize; > > + size_t len; > > + > > + /* While Linux does not care, FreeBSD mlock expects page aligned > > + * address (according to the man). > > + */ > > + pagesize = sysconf(_SC_PAGESIZE); > > + addr = RTE_PTR_ALIGN_FLOOR(_addr, pagesize); > > + len = _len + ((uintptr_t)_addr & (pagesize - 1)); > > + if (mlock(addr, len)) { > > + TESTPMD_LOG(NOTICE, "%s: mlock %p (0x%zx) aligned to %p > > (0x%zx) failed with error \"%s\"\n", > > + prefix, _addr, _len, addr, len, strerror(errno)); > > + } > > +} > > + > > +static int > > +lock_text_cb(struct dl_phdr_info *info, __rte_unused size_t size, > > + __rte_unused void *data) > > +{ > > + int i; > > + > > + for (i = 0; i < info->dlpi_phnum; i++) { > > + void *addr; > > + > > + if (info->dlpi_phdr[i].p_memsz == 0) > > + continue; > > + addr = (void *)(info->dlpi_addr + info->dlpi_phdr[i].p_vaddr); > > + lock_pages(addr, info->dlpi_phdr[i].p_memsz, info->dlpi_name); > > + } > > + return 0; > > +} > > +1 to the idea, testpmd initialization was taking too lock without > '--no-mlockall', but this code looks complex for the application level. > > We can do this for testpmd but does all applications need to do something > similar? If so can we have a solution on eal level instead?
I submitted a patch on the EAL side. This makes mlockall way lighter, since it skips pages marked with PROT_NONE. http://patchwork.dpdk.org/patch/66469/ -- David Marchand
