--- /dev/null
+From 0066b862bb3a09f39295abd5d972a53ac8dc1555 Mon Sep 17 00:00:00 2001
+From: Peter Bergin <peter@berginkonsult.se>
+Date: Wed, 19 Sep 2018 15:12:31 +0200
+Subject: [PATCH] rpm/rpmio.c: restrict virtual memory usage if limit set
+
+A solution to avoid OOM situation when the virtual memory is restricted
+for a user (ulimit -v). As the lzopen_internal function is run in parallel
+one instance per CPU thread the available virtual memory is limited per
+CPU thread.
+
+Upstream-Status: Pending [merge of multithreading patches to upstream]
+
+Signed-off-by: Peter Bergin <peter@berginkonsult.se>
+---
+ rpmio/rpmio.c | 34 ++++++++++++++++++++++++++++++++++
+ 1 file changed, 34 insertions(+)
+
+diff --git a/rpmio/rpmio.c b/rpmio/rpmio.c
+index e051c98..b3c56b6 100644
+--- a/rpmio/rpmio.c
++++ b/rpmio/rpmio.c
+@@ -845,6 +845,40 @@ static LZFILE *lzopen_internal(const char *mode, int fd, int xz)
+ }
+ #endif
+
++ struct rlimit virtual_memory;
++ getrlimit(RLIMIT_AS, &virtual_memory);
++ if (virtual_memory.rlim_cur != RLIM_INFINITY) {
++ const uint64_t virtual_memlimit = virtual_memory.rlim_cur;
++ const uint64_t virtual_memlimit_per_cpu_thread =
++ virtual_memlimit / lzma_cputhreads();
++ uint64_t memory_usage_virt;
++ rpmlog(RPMLOG_NOTICE, "XZ: virtual memory restricted to %lu and "
++ "per CPU thread %lu\n", virtual_memlimit, virtual_memlimit_per_cpu_thread);
++ /* keep reducing the number of compression threads until memory
++ usage falls below the limit per CPU thread*/
++ while ((memory_usage_virt = lzma_stream_encoder_mt_memusage(&mt_options)) >
++ virtual_memlimit_per_cpu_thread) {
++ /* If number of threads goes down to zero lzma_stream_encoder will
++ * will return UINT64_MAX. We must check here to avoid an infinite loop.
++ * If we get into situation that one thread requires more virtual memory
++ * than available we set one thread, print error message and try anyway. */
++ if (--mt_options.threads == 0) {
++ mt_options.threads = 1;
++ rpmlog(RPMLOG_WARNING,
++ "XZ: Could not adjust number of threads to get below "
++ "virtual memory limit %lu. usage %lu\n",
++ virtual_memlimit_per_cpu_thread, memory_usage_virt);
++ break;
++ }
++ }
++ if (threads != (int)mt_options.threads)
++ rpmlog(RPMLOG_NOTICE,
++ "XZ: Adjusted the number of threads from %d to %d to not "
++ "exceed the memory usage limit of %lu bytes\n",
++ threads, mt_options.threads, virtual_memlimit);
++
++ }
++
+ ret = lzma_stream_encoder_mt(&lzfile->strm, &mt_options);
+ }
+ #endif
+--
+2.7.4
+
