valgrind spews

[Jens Axboe <axboe@kernel.dk>]

Hi Bart,

After your commit:

commit 0ffccc21fcd67d1e1d2a360e90f3fe8efc0d6b52
Author: Bart Van Assche <bart.vanassche@wdc.com>
Date:   Thu Mar 8 13:41:36 2018 -0800

    Improve Valgrind instrumentation of memory allocations

running valgrind on a fio spews a lot of warnings:

==14331== Invalid write of size 8
==14331==    at 0x4C3451F: memset (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==14331==    by 0x4595F8: memset (string3.h:90)
==14331==    by 0x4595F8: smalloc_pool (smalloc.c:434)
==14331==    by 0x4595F8: __smalloc (smalloc.c:452)
==14331==    by 0x4727CD: flow_init (flow.c:112)
==14331==    by 0x421886: setup_thread_area (init.c:391)
==14331==    by 0x42552A: get_new_job (init.c:468)
==14331==    by 0x42552A: __parse_jobs_ini (init.c:1928)
==14331==    by 0x42585F: parse_jobs_ini (init.c:2082)
[...]

Basically off any path that ends up in smalloc, on the memset()
that we do:

        ptr = __smalloc_pool(pool, alloc_size);
        if (ptr) {
                struct block_hdr *hdr = ptr;

                hdr->size = alloc_size;
                fill_redzone(hdr);

                ptr += sizeof(*hdr);
                memset(ptr, 0, size);
		^^^
        }

for every alloc. From configure:

Valgrind headers              yes


-- 
Jens Axboe