Re: [libvirt] [PATCH] fix size parameter in calls to numa_node_to_cpus

Dave Allan <dallan(a)redhat.com&gt; wrote: > I was getting the error: > > map size mismatch; abort > > when running the daemon-conf tests. > > I traced it to two places in which we were passing a parameter as a > number of bits to numa_node_to_cpus which expects a number of bytes > (see numa_node_to_cpus_compat in numa.h in the numactl source). > > The attached patch fixes the problem. > > Dave > diff --git a/src/qemu_conf.c b/src/qemu_conf.c > index e6c378f..7019c14 100644 > --- a/src/qemu_conf.c > +++ b/src/qemu_conf.c > @@ -324,7 +324,7 @@ qemudCapsInitNUMA(virCapsPtr caps) > > for (n = 0 ; n <= numa_max_node() ; n++) { > > - if (numa_node_to_cpus(n, mask, MAX_CPUS_MASK_LEN) < 0) > + if (numa_node_to_cpus(n, mask, MAX_CPUS_MASK_LEN / 8) < 0) Hi Dave, [Sorry I didn't catch this earlier. ] With that patch, I am now seeing that out of memory message in "make check" test failures, e.g., testing with corrupted config: min_workers --- expected-err 2008-12-12 15:30:20.000000000 +0100 +++ err 2008-12-12 15:30:20.000000000 +0100 @@ -1,2 +1,5 @@ +map size mismatch; abort +: Success +umlStartup: out of memory remoteReadConfigFile: in23.conf: min_workers: invalid type: got string; expected long Since we're using NUMA_VERSION1_COMPATIBILITY mode (anyone know why?) #if HAVE_NUMACTL #define NUMA_VERSION1_COMPATIBILITY 1 #include <numa.h> #endif numa_node_to_cpus expands to a call to numa_node_to_cpus_compat, which is defined in numa.h: static inline int numa_node_to_cpus_compat(int node, unsigned long *buffer, int buffer_len) { struct bitmask tmp; tmp.maskp = (unsigned long *)buffer; tmp.size = buffer_len * 8; return numa_node_to_cpus(node, &tmp); } So the question is, what units to use in "tmp.size". To answer that, I looked above, also in numa.h at this: struct bitmask { unsigned long size; /* number of bits in the map */ unsigned long *maskp; }; And since MAX_CPUS_MASK_LEN is a buffer length, in bytes, from qemu_conf.c: qemudCapsInitNUMA(virCapsPtr caps) { ... if (VIR_ALLOC_N(mask, MAX_CPUS_MASK_LEN) < 0) goto cleanup; and tmp.size is measured in bits, we have to continue to use that MAX_CPUS_MASK_LEN parameter, and not divide it by 8: So I propose this change: (with it, "make check" does pass once again) From ceae19496cd60bd9a7b3527046b42e9f8460ae82 Mon Sep 17 00:00:00 2001 From: Jim Meyering <meyering(a)redhat.com&gt; Date: Fri, 12 Dec 2008 16:22:34 +0100 Subject: [PATCH] Revert "fix bits/bytes memory request mismatches" * src/qemu_conf.c (qemudCapsInitNUMA): Do pass MAX_CPUS_MASK_LEN as buffer length in call to numa_node_to_cpus. * src/uml_conf.c (umlCapsInitNUMA): Likewise. --- src/qemu_conf.c | 2 +- src/uml_conf.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/src/qemu_conf.c b/src/qemu_conf.c index 59171e7..206fb0b 100644 --- a/src/qemu_conf.c +++ b/src/qemu_conf.c @@ -324,7 +324,7 @@ qemudCapsInitNUMA(virCapsPtr caps) for (n = 0 ; n <= numa_max_node() ; n++) { - if (numa_node_to_cpus(n, mask, MAX_CPUS_MASK_LEN / 8) < 0) + if (numa_node_to_cpus(n, mask, MAX_CPUS_MASK_LEN) < 0) goto cleanup; for (ncpus = 0, i = 0 ; i < MAX_CPUS ; i++) diff --git a/src/uml_conf.c b/src/uml_conf.c index 3659c6b..7eb630d 100644 --- a/src/uml_conf.c +++ b/src/uml_conf.c @@ -80,7 +80,7 @@ umlCapsInitNUMA(virCapsPtr caps) for (n = 0 ; n <= numa_max_node() ; n++) { - if (numa_node_to_cpus(n, mask, MAX_CPUS_MASK_LEN / 8) < 0) + if (numa_node_to_cpus(n, mask, MAX_CPUS_MASK_LEN) < 0) goto cleanup; for (ncpus = 0, i = 0 ; i < MAX_CPUS ; i++) -- 1.6.0.4.1044.g77718