diff --git a/glibc-testsuite.changes b/glibc-testsuite.changes
index 286bb78..28e6771 100644
--- a/glibc-testsuite.changes
+++ b/glibc-testsuite.changes
@@ -1,3 +1,9 @@
+-------------------------------------------------------------------
+Wed Apr 8 12:50:39 UTC 2015 - mgorman@suse.com
+
+- threaded-trim-threshold.patch: Fix regression in threaded application
+ malloc performance (bsc#915955, BZ #17195)
+
-------------------------------------------------------------------
Thu Apr 2 08:11:20 UTC 2015 - schwab@suse.de
diff --git a/glibc-testsuite.spec b/glibc-testsuite.spec
index b6ba37f..bd58940 100644
--- a/glibc-testsuite.spec
+++ b/glibc-testsuite.spec
@@ -243,6 +243,8 @@ Patch1003: pthread-mutexattr-gettype-kind.patch
Patch1004: powerpc-software-sqrt.patch
# PATCH-FIX-UPSTREAM Fix DTV race, assert, DTV_SURPLUS Static TLS limit, and nptl_db garbage (bsc#919678, BZ #17090, BZ #17620, BZ #17621, BZ #17628)
Patch1005: static-tls-dtv-limit.patch
+# PATCH-FIX-UPSTREAM Fix regression in threaded application malloc performance (bsc#915955, BZ #17195)
+Patch1006: threaded-trim-threshold.patch
###
# Patches awaiting upstream approval
@@ -469,6 +471,7 @@ rm nscd/s-stamp
%patch1003 -p1
%patch1004 -p1
%patch1005 -p1
+%patch1006 -p1
%patch2000 -p1
%patch2002 -p1
diff --git a/glibc-utils.changes b/glibc-utils.changes
index 286bb78..28e6771 100644
--- a/glibc-utils.changes
+++ b/glibc-utils.changes
@@ -1,3 +1,9 @@
+-------------------------------------------------------------------
+Wed Apr 8 12:50:39 UTC 2015 - mgorman@suse.com
+
+- threaded-trim-threshold.patch: Fix regression in threaded application
+ malloc performance (bsc#915955, BZ #17195)
+
-------------------------------------------------------------------
Thu Apr 2 08:11:20 UTC 2015 - schwab@suse.de
diff --git a/glibc-utils.spec b/glibc-utils.spec
index 4d14ed7..b5ae5d1 100644
--- a/glibc-utils.spec
+++ b/glibc-utils.spec
@@ -242,6 +242,8 @@ Patch1003: pthread-mutexattr-gettype-kind.patch
Patch1004: powerpc-software-sqrt.patch
# PATCH-FIX-UPSTREAM Fix DTV race, assert, DTV_SURPLUS Static TLS limit, and nptl_db garbage (bsc#919678, BZ #17090, BZ #17620, BZ #17621, BZ #17628)
Patch1005: static-tls-dtv-limit.patch
+# PATCH-FIX-UPSTREAM Fix regression in threaded application malloc performance (bsc#915955, BZ #17195)
+Patch1006: threaded-trim-threshold.patch
###
# Patches awaiting upstream approval
@@ -469,6 +471,7 @@ rm nscd/s-stamp
%patch1003 -p1
%patch1004 -p1
%patch1005 -p1
+%patch1006 -p1
%patch2000 -p1
%patch2002 -p1
diff --git a/glibc.changes b/glibc.changes
index 286bb78..28e6771 100644
--- a/glibc.changes
+++ b/glibc.changes
@@ -1,3 +1,9 @@
+-------------------------------------------------------------------
+Wed Apr 8 12:50:39 UTC 2015 - mgorman@suse.com
+
+- threaded-trim-threshold.patch: Fix regression in threaded application
+ malloc performance (bsc#915955, BZ #17195)
+
-------------------------------------------------------------------
Thu Apr 2 08:11:20 UTC 2015 - schwab@suse.de
diff --git a/glibc.spec b/glibc.spec
index f7d1dbf..e10f095 100644
--- a/glibc.spec
+++ b/glibc.spec
@@ -243,6 +243,8 @@ Patch1003: pthread-mutexattr-gettype-kind.patch
Patch1004: powerpc-software-sqrt.patch
# PATCH-FIX-UPSTREAM Fix DTV race, assert, DTV_SURPLUS Static TLS limit, and nptl_db garbage (bsc#919678, BZ #17090, BZ #17620, BZ #17621, BZ #17628)
Patch1005: static-tls-dtv-limit.patch
+# PATCH-FIX-UPSTREAM Fix regression in threaded application malloc performance (bsc#915955, BZ #17195)
+Patch1006: threaded-trim-threshold.patch
###
# Patches awaiting upstream approval
@@ -469,6 +471,7 @@ rm nscd/s-stamp
%patch1003 -p1
%patch1004 -p1
%patch1005 -p1
+%patch1006 -p1
%patch2000 -p1
%patch2002 -p1
diff --git a/threaded-trim-threshold.patch b/threaded-trim-threshold.patch
new file mode 100644
index 0000000..4457442
--- /dev/null
+++ b/threaded-trim-threshold.patch
@@ -0,0 +1,224 @@
+From c26efef9798914e208329c0e8c3c73bb1135d9e3 Mon Sep 17 00:00:00 2001
+From: Mel Gorman <mgorman@suse.de>
+Date: Thu, 2 Apr 2015 12:14:14 +0530
+Subject: [PATCH] malloc: Consistently apply trim_threshold to all heaps [BZ
+ #17195]
+
+Trimming heaps is a balance between saving memory and the system overhead
+required to update page tables and discard allocated pages. The malloc
+option M_TRIM_THRESHOLD is a tunable that users are meant to use to decide
+where this balance point is but it is only applied to the main arena.
+
+For scalability reasons, glibc malloc has per-thread heaps but these are
+shrunk with madvise() if there is one page free at the top of the heap.
+In some circumstances this can lead to high system overhead if a thread
+has a control flow like
+
+ while (data_to_process) {
+ buf = malloc(large_size);
+ do_stuff();
+ free(buf);
+ }
+
+For a large size, the free() will call madvise (pagetable teardown, page
+free and TLB flush) every time followed immediately by a malloc (fault,
+kernel page alloc, zeroing and charge accounting). The kernel overhead
+can dominate such a workload.
+
+This patch allows the user to tune when madvise gets called by applying
+the trim threshold to the per-thread heaps and using similar logic to the
+main arena when deciding whether to shrink. Alternatively if the dynamic
+brk/mmap threshold gets adjusted then the new values will be obeyed by
+the per-thread heaps.
+
+Bug 17195 was a test case motivated by a problem encountered in scientific
+applications written in python that performance badly due to high page fault
+overhead. The basic operation of such a program was posted by Julian Taylor
+https://sourceware.org/ml/libc-alpha/2015-02/msg00373.html
+
+With this patch applied, the overhead is eliminated. All numbers in this
+report are in seconds and were recorded by running Julian's program 30
+times.
+
+pyarray
+ glibc madvise
+ 2.21 v2
+System min 1.81 ( 0.00%) 0.00 (100.00%)
+System mean 1.93 ( 0.00%) 0.02 ( 99.20%)
+System stddev 0.06 ( 0.00%) 0.01 ( 88.99%)
+System max 2.06 ( 0.00%) 0.03 ( 98.54%)
+Elapsed min 3.26 ( 0.00%) 2.37 ( 27.30%)
+Elapsed mean 3.39 ( 0.00%) 2.41 ( 28.84%)
+Elapsed stddev 0.14 ( 0.00%) 0.02 ( 82.73%)
+Elapsed max 4.05 ( 0.00%) 2.47 ( 39.01%)
+
+ glibc madvise
+ 2.21 v2
+User 141.86 142.28
+System 57.94 0.60
+Elapsed 102.02 72.66
+
+Note that almost a minutes worth of system time is eliminted and the
+program completes 28% faster on average.
+
+To illustrate the problem without python this is a basic test-case for
+the worst case scenario where every free is a madvise followed by a an alloc
+
+/* gcc bench-free.c -lpthread -o bench-free */
+static int num = 1024;
+
+void __attribute__((noinline,noclone)) dostuff (void *p)
+{
+}
+
+void *worker (void *data)
+{
+ int i;
+
+ for (i = num; i--;)
+ {
+ void *m = malloc (48*4096);
+ dostuff (m);
+ free (m);
+ }
+
+ return NULL;
+}
+
+int main()
+{
+ int i;
+ pthread_t t;
+ void *ret;
+ if (pthread_create (&t, NULL, worker, NULL))
+ exit (2);
+ if (pthread_join (t, &ret))
+ exit (3);
+ return 0;
+}
+
+Before the patch, this resulted in 1024 calls to madvise. With the patch applied,
+madvise is called twice because the default trim threshold is high enough to avoid
+this.
+
+This a more complex case where there is a mix of frees. It's simply a different worker
+function for the test case above
+
+void *worker (void *data)
+{
+ int i;
+ int j = 0;
+ void *free_index[num];
+
+ for (i = num; i--;)
+ {
+ void *m = malloc ((i % 58) *4096);
+ dostuff (m);
+ if (i % 2 == 0) {
+ free (m);
+ } else {
+ free_index[j++] = m;
+ }
+ }
+ for (; j >= 0; j--)
+ {
+ free(free_index[j]);
+ }
+
+ return NULL;
+}
+
+glibc 2.21 calls malloc 90305 times but with the patch applied, it's
+called 13438. Increasing the trim threshold will decrease the number of
+times it's called with the option of eliminating the overhead.
+
+ebizzy is meant to generate a workload resembling common web application
+server workloads. It is threaded with a large working set that at its core
+has an allocation, do_stuff, free loop that also hits this case. The primary
+metric of the benchmark is records processed per second. This is running on
+my desktop which is a single socket machine with an I7-4770 and 8 cores.
+Each thread count was run for 30 seconds. It was only run once as the
+performance difference is so high that the variation is insignificant.
+
+ glibc 2.21 patch
+threads 1 10230 44114
+threads 2 19153 84925
+threads 4 34295 134569
+threads 8 51007 183387
+
+Note that the saving happens to be a concidence as the size allocated
+by ebizzy was less than the default threshold. If a different number of
+chunks were specified then it may also be necessary to tune the threshold
+to compensate
+
+This is roughly quadrupling the performance of this benchmark. The difference in
+system CPU usage illustrates why.
+
+ebizzy running 1 thread with glibc 2.21
+10230 records/s 306904
+real 30.00 s
+user 7.47 s
+sys 22.49 s
+
+22.49 seconds was spent in the kernel for a workload runinng 30 seconds. With the
+patch applied
+
+ebizzy running 1 thread with patch applied
+44126 records/s 1323792
+real 30.00 s
+user 29.97 s
+sys 0.00 s
+
+system CPU usage was zero with the patch applied. strace shows that glibc
+running this workload calls madvise approximately 9000 times a second. With
+the patch applied madvise was called twice during the workload (or 0.06
+times per second).
+
+2015-02-10 Mel Gorman <mgorman@suse.de>
+
+ [BZ #17195]
+ * malloc/arena.c (free): Apply trim threshold to per-thread heaps
+ as well as the main arena.
+---
+
+--- a/malloc/malloc.c
++++ b/malloc/malloc.c
+@@ -241,6 +241,8 @@
+ /* For MIN, MAX, powerof2. */
+ #include <sys/param.h>
+
++/* For ALIGN_DOWN. */
++#include <libc-internal.h>
+
+ /*
+ Debugging:
+--- a/malloc/arena.c
++++ b/malloc/arena.c
+@@ -658,7 +658,7 @@ heap_trim (heap_info *heap, size_t pad)
+ unsigned long pagesz = GLRO (dl_pagesize);
+ mchunkptr top_chunk = top (ar_ptr), p, bck, fwd;
+ heap_info *prev_heap;
+- long new_size, top_size, extra, prev_size, misalign;
++ long new_size, top_size, top_area, extra, prev_size, misalign;
+
+ /* Can this heap go away completely? */
+ while (top_chunk == chunk_at_offset (heap, sizeof (*heap)))
+@@ -694,9 +694,16 @@ heap_trim (heap_info *heap, size_t pad)
+ set_head (top_chunk, new_size | PREV_INUSE);
+ /*check_chunk(ar_ptr, top_chunk);*/
+ }
++
++ /* Uses similar logic for per-thread arenas as the main arena with systrim
++ by preserving the top pad and at least a page. */
+ top_size = chunksize (top_chunk);
+- extra = (top_size - pad - MINSIZE - 1) & ~(pagesz - 1);
+- if (extra < (long) pagesz)
++ top_area = top_size - MINSIZE - 1;
++ if (top_area <= pad)
++ return 0;
++
++ extra = ALIGN_DOWN(top_area - pad, pagesz);
++ if ((unsigned long) extra < mp_.trim_threshold)
+ return 0;
+
+ /* Try to shrink. */