Re: [Qemu-devel] [PATCH v7 08/35] exec: allow memory to be allocated from any kind of path

[Vladimir Sementsov-Ogievskiy]

On 02.11.2015 18:22, Xiao Guangrong wrote:
> On 11/02/2015 10:51 PM, Vladimir Sementsov-Ogievskiy wrote:
> > On 02.11.2015 12:13, Xiao Guangrong wrote:
> > > Currently file_ram_alloc() is designed for hugetlbfs, however, the 
> > > memory
> > > of nvdimm can come from either raw pmem device eg, /dev/pmem, or the 
> > > file
> > > locates at DAX enabled filesystem
> > >
> > > So this patch let it work on any kind of path
> >
> > No, this patch doesn't change any logic, but only fix variable name 
> > and some error messages.
>
> Yes, it is.
>
> 'let it work' in my thought exactly was "fix variable name and some 
> error messages"... okay,
> if it confused you, how about change it to:
>
> "This patch fixes variable name and some error messages to let it be 
> aware of normal
> path"

My english is not very good, I don't know figures of speech. For me 
"patch let it work" means that without this patch it will not work))
Your new variant is ok for me, or better (imo) "This patch fixes 
variable name and some error messages to be suitable for any kind of path"

> > > Signed-off-by: Xiao Guangrong <address@hidden>
> > > ---
> > >   exec.c | 24 ++++++++++++------------
> > >   1 file changed, 12 insertions(+), 12 deletions(-)
> > >
> > > diff --git a/exec.c b/exec.c
> > > index 9de38be..9075f4d 100644
> > > --- a/exec.c
> > > +++ b/exec.c
> > > @@ -1184,25 +1184,25 @@ static void *file_ram_alloc(RAMBlock *block,
> > >       char *c;
> > >       void *area;
> > >       int fd;
> > > -    uint64_t hpagesize;
> > > +    uint64_t pagesize;
> > >       Error *local_err = NULL;
> > > -    hpagesize = qemu_file_get_page_size(path, &local_err);
> > > +    pagesize = qemu_file_get_page_size(path, &local_err);
> > >       if (local_err) {
> > >           error_propagate(errp, local_err);
> > >           goto error;
> > >       }
> > > -    if (hpagesize == getpagesize()) {
> > > -        fprintf(stderr, "Warning: path not on HugeTLBFS: %s\n", path);
> > > +    if (pagesize == getpagesize()) {
> > > +        fprintf(stderr, "Memory is not allocated from HugeTlbfs.\n");
> >
> > Why do you remove path from error message? It is good additional 
> > information.. What if we have
> > several memory file backends?
>
> Good catch, will change it to:
> fprintf(stderr, "Memory is not allocated from HugeTlbfs on path 
> %s.\n", path);
>
> BTW, if no other big change in the further, i will post the new 
> version just for of this patch,
>
> > >       }
> > > -    block->mr->align = hpagesize;
> > > +    block->mr->align = pagesize;
> > > -    if (memory < hpagesize) {
> > > +    if (memory < pagesize) {
> > >           error_setg(errp, "memory size 0x" RAM_ADDR_FMT " must be 
> > > equal to "
> > > -                   "or larger than huge page size 0x%" PRIx64,
> > > -                   memory, hpagesize);
> > > +                   "or larger than page size 0x%" PRIx64,
> > > +                   memory, pagesize);
> > >           goto error;
> > >       }
> > > @@ -1226,14 +1226,14 @@ static void *file_ram_alloc(RAMBlock *block,
> > >       fd = mkstemp(filename);
> > >       if (fd < 0) {
> > >           error_setg_errno(errp, errno,
> > > -                         "unable to create backing store for 
> > > hugepages");
> > > +                         "unable to create backing store for path 
> > > %s", path);
> > >           g_free(filename);
> > >           goto error;
> > >       }
> > >       unlink(filename);
> > >       g_free(filename);
> > > -    memory = ROUND_UP(memory, hpagesize);
> > > +    memory = ROUND_UP(memory, pagesize);
> > >       /*
> > >        * ftruncate is not supported by hugetlbfs in older
> > > @@ -1245,10 +1245,10 @@ static void *file_ram_alloc(RAMBlock *block,
> > >           perror("ftruncate");
> > >       }
> > > -    area = qemu_ram_mmap(fd, memory, hpagesize, block->flags & 
> > > RAM_SHARED);
> > > +    area = qemu_ram_mmap(fd, memory, pagesize, block->flags & 
> > > RAM_SHARED);
> > >       if (area == MAP_FAILED) {
> > >           error_setg_errno(errp, errno,
> > > -                         "unable to map backing store for hugepages");
> > > +                         "unable to map backing store for path %s", 
> > > path);
> > >           close(fd);
> > >           goto error;
> > >       }

With these two fixes (any commit message variant):

Reviewed-by: Vladimir Sementsov-Ogievskiy <address@hidden>

--
Best regards,
Vladimir
* now, @virtuozzo.com instead of @parallels.com. Sorry for this inconvenience.