The patch titled Subject: mm/vmalloc: fix performance regression caused by needless vmalloc_sync_all() has been removed from the -mm tree. Its filename was mm-vmalloc-fix-regression-caused-by-needless-vmalloc_sync_all.patch
This patch was dropped because an alternative patch was merged
------------------------------------------------------ From: Shile Zhang shile.zhang@linux.alibaba.com Subject: mm/vmalloc: fix performance regression caused by needless vmalloc_sync_all()
vmalloc_sync_all() was put in the common path in __purge_vmap_area_lazy(), for one sync issue only happened on X86_32 with PTI enabled. It is needless for X86_64, which caused a big regression in UnixBench Shell8 testing on X86_64. Similar regression also reported by 0-day kernel test robot in reaim benchmarking: https://lists.01.org/hyperkitty/list/lkp@lists.01.org/thread/4D3JPPHBNOSPFK2...
Fix it by adding more conditions.
[akpm@linux-foundation.org: simplify config expression, use IS_ENABLED()] [akpm@linux-foundation.org: build fix - go back to using an ifdef] Link: http://lkml.kernel.org/r/20191113095530.228959-1-shile.zhang@linux.alibaba.c... Fixes: 3f8fd02b1bf1 ("mm/vmalloc: Sync unmappings in __purge_vmap_area_lazy()") Signed-off-by: Shile Zhang shile.zhang@linux.alibaba.com Cc: Joerg Roedel jroedel@suse.de Cc: Qian Cai cai@lca.pw Cc: Thomas Gleixner tglx@linutronix.de Cc: Dave Hansen dave.hansen@linux.intel.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---
mm/vmalloc.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-)
--- a/mm/vmalloc.c~mm-vmalloc-fix-regression-caused-by-needless-vmalloc_sync_all +++ a/mm/vmalloc.c @@ -1255,11 +1255,17 @@ static bool __purge_vmap_area_lazy(unsig if (unlikely(valist == NULL)) return false;
+#ifdef CONFIG_X86_PAE /* - * First make sure the mappings are removed from all page-tables - * before they are freed. + * First make sure the mappings are removed from all pagetables before + * they are freed. + * + * This is only needed on x86-32 with !SHARED_KERNEL_PMD, which is the + * case on a PAE kernel with PTI enabled. */ - vmalloc_sync_all(); + if (!SHARED_KERNEL_PMD && boot_cpu_has(X86_FEATURE_PTI)) + vmalloc_sync_all(); +#endif
/* * TODO: to calculate a flush range without looping. _
Patches currently in -mm which might be from shile.zhang@linux.alibaba.com are