lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Thu, 12 Mar 2020 14:12:14 -0300 From: Arnaldo Carvalho de Melo <arnaldo.melo@...il.com> To: Alexey Budankov <alexey.budankov@...ux.intel.com> Cc: Arnaldo Carvalho de Melo <arnaldo.melo@...il.com>, Jiri Olsa <jolsa@...hat.com>, Namhyung Kim <namhyung@...nel.org>, Alexander Shishkin <alexander.shishkin@...ux.intel.com>, Peter Zijlstra <peterz@...radead.org>, Ingo Molnar <mingo@...hat.com>, Andi Kleen <ak@...ux.intel.com>, linux-kernel <linux-kernel@...r.kernel.org> Subject: Re: [PATCH v1] perf record: fix binding of AIO user space buffers to nodes Em Thu, Mar 12, 2020 at 07:09:56PM +0300, Alexey Budankov escreveu: > > On 12.03.2020 17:31, Arnaldo Carvalho de Melo wrote: > > Em Thu, Mar 12, 2020 at 03:21:45PM +0300, Alexey Budankov escreveu: > >> > >> Correct maxnode parameter value passed to mbind() syscall to be > >> the amount of node mask bits to analyze plus 1. Dynamically allocate > >> node mask memory depending on the index of node of cpu being profiled. > >> Fixes: c44a8b44ca9f ("perf record: Bind the AIO user space buffers to nodes") > >> Signed-off-by: Alexey Budankov <alexey.budankov@...ux.intel.com> > >> --- > >> tools/perf/util/mmap.c | 21 +++++++++++++++------ > >> 1 file changed, 15 insertions(+), 6 deletions(-) > >> > >> diff --git a/tools/perf/util/mmap.c b/tools/perf/util/mmap.c > >> index 3b664fa673a6..6d604cd67a95 100644 > >> --- a/tools/perf/util/mmap.c > >> +++ b/tools/perf/util/mmap.c > >> @@ -98,20 +98,29 @@ static int perf_mmap__aio_bind(struct mmap *map, int idx, int cpu, int affinity) > >> { > >> void *data; > >> size_t mmap_len; > >> - unsigned long node_mask; > >> + unsigned long *node_mask; > >> + unsigned long node_index; > >> + int err = 0; > >> > >> if (affinity != PERF_AFFINITY_SYS && cpu__max_node() > 1) { > >> data = map->aio.data[idx]; > >> mmap_len = mmap__mmap_len(map); > >> - node_mask = 1UL << cpu__get_node(cpu); > >> - if (mbind(data, mmap_len, MPOL_BIND, &node_mask, 1, 0)) { > >> - pr_err("Failed to bind [%p-%p] AIO buffer to node %d: error %m\n", > >> - data, data + mmap_len, cpu__get_node(cpu)); > >> + node_index = cpu__get_node(cpu); > >> + node_mask = bitmap_alloc(node_index + 1); > >> + if (!node_mask) { > >> + pr_err("Failed to allocate node mask for mbind: error %m\n"); > >> return -1; > >> } > >> + set_bit(node_index, node_mask); > >> + if (mbind(data, mmap_len, MPOL_BIND, node_mask, node_index + 1 + 1/*nr_bits + 1*/, 0)) { > > > > ^^^^^^^^^^^^^^ > > Leftover? > > Intentionally put it here to document kernel behavior for mbind() syscall > because currently it is different from the man page [1] documented: > > "nodemask points to a bit mask of nodes containing up to maxnode bits. > The bit mask size is rounded to the next multiple of sizeof(unsigned > long), but the kernel will use bits only up to maxnode. A NULL value > of nodemask or a maxnode value of zero specifies the empty set of > nodes. If the value of maxnode is zero, the nodemask argument is > ignored. Where a nodemask is required, it must contain at least one > node that is on-line, allowed by the thread's current cpuset context > (unless the MPOL_F_STATIC_NODES mode flag is specified), and contains > memory." Ok, will add the above as a comment above the line with that comment. > ~Alexey > > [1] http://man7.org/linux/man-pages/man2/mbind.2.html -- - Arnaldo
Powered by blists - more mailing lists