On Fri, Jul 17, 2015 at 18:13:26 +0200, Andrea Bolognani wrote:
> Swap out all instances of cpu_set_t and replace them with virBitmap,
> which some of the code was already using anyway.
>
> The changes are pretty mechanical, with one notable exception: an
> assumption has been added on the max value we can run into while
> reading either socket_it or core_id.
>
> While this specific assumption was not in place before, we were
> using cpu_set_t improperly by not making sure not to set any bit
> past CPU_SETSIZE or explicitly allocating bigger bitmaps; in fact
> the default size of a cpu_set_t, 1024, is way too low to run our
> testsuite, which includes core_id values in the 2000s.
> ---
> src/nodeinfo.c | 65 ++++++++++++++++++++++++++++++++++------------------------
> 1 file changed, 38 insertions(+), 27 deletions(-)
>
> diff --git a/src/nodeinfo.c b/src/nodeinfo.c
> index 44983b8..61a3b33 100644
> --- a/src/nodeinfo.c
> +++ b/src/nodeinfo.c
> @@ -30,7 +30,6 @@
> #include <errno.h>
> #include <dirent.h>
> #include <sys/utsname.h>
> -#include <sched.h>
> #include "conf/domain_conf.h"
>
> #if defined(__FreeBSD__) || defined(__APPLE__)
> @@ -388,19 +387,6 @@ virNodeParseSocket(const char *dir,
> return ret;
> }
>
> -# ifndef CPU_COUNT
> -static int
> -CPU_COUNT(cpu_set_t *set)
> -{
> - size_t i, count = 0;
> -
> - for (i = 0; i < CPU_SETSIZE; i++)
> - if (CPU_ISSET(i, set))
> - count++;
> - return count;
> -}
> -# endif /* !CPU_COUNT */
> -
> /* parses a node entry, returning number of processors in the node and
> * filling arguments */
> static int
> @@ -415,15 +401,18 @@ virNodeParseNode(const char *sysfs_prefix,
> int *threads,
> int *offline)
> {
> + /* Biggest value we can expect to be used as either socket id
> + * or core id. Bitmaps will need to be sized accordingly */
> + const int ID_MAX = 4095;
I think this should be a more global setting. We have quite a few places
where we invent arbitrary maximum cpu counts. One of them is
virProcessSetAffinity.
> int ret = -1;
> int processors = 0;
> DIR *cpudir = NULL;
> struct dirent *cpudirent = NULL;
> virBitmapPtr present_cpumap = NULL;
> + virBitmapPtr sockets_map = NULL;
> + virBitmapPtr *cores_maps = NULL;
> int sock_max = 0;
> - cpu_set_t sock_map;
> int sock;
> - cpu_set_t *core_maps = NULL;
> int core;
> size_t i;
> int siblings;
> @@ -445,7 +434,9 @@ virNodeParseNode(const char *sysfs_prefix,
> goto cleanup;
>
> /* enumerate sockets in the node */
> - CPU_ZERO(&sock_map);
> + if (!(sockets_map = virBitmapNew(ID_MAX + 1)))
> + goto cleanup;
> +
> while ((direrr = virDirRead(cpudir, &cpudirent, node)) > 0) {
> if (sscanf(cpudirent->d_name, "cpu%u", &cpu) != 1)
> continue;
> @@ -462,7 +453,15 @@ virNodeParseNode(const char *sysfs_prefix,
> /* Parse socket */
> if ((sock = virNodeParseSocket(node, arch, cpu)) < 0)
> goto cleanup;
> - CPU_SET(sock, &sock_map);
> + if (sock > ID_MAX) {
> + virReportError(VIR_ERR_INTERNAL_ERROR,
> + _("Socket %d can't be handled (max socket is %d)"),
> + sock, ID_MAX);
> + goto cleanup;
> + }
> +
> + if (virBitmapSetBit(sockets_map, sock) < 0)
> + goto cleanup;
Like many others, this code would benefit from auto-allocating bitmaps
rather than the static ones. Nothing to change though here.
>
> if (sock > sock_max)
> sock_max = sock;
Otherwise looks good to me, but I'd really want to avoid multiple
definitions of the same maximum variable.
Peter
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