Joerg Roedel 763802b53a x86/mm: split vmalloc_sync_all() ... Commit 3f8fd02b1b ("mm/vmalloc: Sync unmappings in __purge_vmap_area_lazy()") introduced a call to vmalloc_sync_all() in the vunmap() code-path. While this change was necessary to maintain correctness on x86-32-pae kernels, it also adds additional cycles for architectures that don't need it. Specifically on x86-64 with CONFIG_VMAP_STACK=y some people reported severe performance regressions in micro-benchmarks because it now also calls the x86-64 implementation of vmalloc_sync_all() on vunmap(). But the vmalloc_sync_all() implementation on x86-64 is only needed for newly created mappings. To avoid the unnecessary work on x86-64 and to gain the performance back, split up vmalloc_sync_all() into two functions: * vmalloc_sync_mappings(), and * vmalloc_sync_unmappings() Most call-sites to vmalloc_sync_all() only care about new mappings being synchronized. The only exception is the new call-site added in the above mentioned commit. Shile Zhang directed us to a report of an 80% regression in reaim throughput. Fixes: 3f8fd02b1b ("mm/vmalloc: Sync unmappings in __purge_vmap_area_lazy()") Reported-by: kernel test robot <oliver.sang@intel.com> Reported-by: Shile Zhang <shile.zhang@linux.alibaba.com> Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Tested-by: Borislav Petkov <bp@suse.de> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> [GHES] Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/20191009124418.8286-1-joro@8bytes.org Link: https://lists.01.org/hyperkitty/list/lkp@lists.01.org/thread/4D3JPPHBNOSPFK2KEPC6KGKS6J25AIDB/ Link: http://lkml.kernel.org/r/20191113095530.228959-1-shile.zhang@linux.alibaba.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2020-03-21 18:56:06 -07:00
..
Kconfig	ACPI / APEI: Switch NOTIFY_SEA to use the estatus queue	2019-02-07 23:10:45 +01:00
Makefile	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
apei-base.c	acpi: Use pr_warn instead of pr_warning	2019-10-18 15:00:19 +02:00
apei-internal.h	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
bert.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 437	2019-06-05 17:37:17 +02:00
einj.c	acpi: Use pr_warn instead of pr_warning	2019-10-18 15:00:19 +02:00
erst-dbg.c	acpi: Use pr_warn instead of pr_warning	2019-10-18 15:00:19 +02:00
erst.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174	2019-05-30 11:26:41 -07:00
ghes.c	x86/mm: split vmalloc_sync_all()	2020-03-21 18:56:06 -07:00
hest.c	acpi: Use pr_warn instead of pr_warning	2019-10-18 15:00:19 +02:00