Remove the extra tab in __flush_tlb_one(). CC: Alex Shi <alex.shi@intel.com> CC: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Michael Wang <wangyun@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/51AD8902.60603@linux.vnet.ibm.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This function is called in __native_flush_tlb_global() and after apply_microcode_early(). Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Link: http://lkml.kernel.org/r/1356075872-3054-8-git-send-email-fenghua.yu@intel.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
All 486+ CPUs support INVLPG, so remove the fallback 386 support code. Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Link: http://lkml.kernel.org/r/1354132230-21854-6-git-send-email-hpa@linux.intel.com
The incompatible parameter of flush_tlb_mm_range cause build warning. Fix it by correct parameter. Ingo Molnar found that this could also cause a user space crash. Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Alex Shi <alex.shi@intel.com> Link: http://lkml.kernel.org/r/1342747103-19765-1-git-send-email-alex.shi@intel.com Signed-off-by: H. Peter Anvin <hpa@zytor.com>
This patch do flush_tlb_kernel_range by 'invlpg'. The performance pay and gain was analyzed in previous patch (x86/flush_tlb: try flush_tlb_single one by one in flush_tlb_range). In the testing: http://lkml.org/lkml/2012/6/21/10 The pay is mostly covered by long kernel path, but the gain is still quite clear, memory access in user APP can increase 30+% when kernel execute this funtion. Signed-off-by: Alex Shi <alex.shi@intel.com> Link: http://lkml.kernel.org/r/1340845344-27557-10-git-send-email-alex.shi@intel.com Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Not every tlb_flush execution moment is really need to evacuate all
TLB entries, like in munmap, just few 'invlpg' is better for whole
process performance, since it leaves most of TLB entries for later
accessing.
This patch also rewrite flush_tlb_range for 2 purposes:
1, split it out to get flush_blt_mm_range function.
2, clean up to reduce line breaking, thanks for Borislav's input.
My micro benchmark 'mummap' http://lkml.org/lkml/2012/5/17/59
show that the random memory access on other CPU has 0~50% speed up
on a 2P * 4cores * HT NHM EP while do 'munmap'.
Thanks Yongjie's testing on this patch:
-------------
I used Linux 3.4-RC6 w/ and w/o his patches as Xen dom0 and guest
kernel.
After running two benchmarks in Xen HVM guest, I found his patches
brought about 1%~3% performance gain in 'kernel build' and 'netperf'
testing, though the performance gain was not very stable in 'kernel
build' testing.
Some detailed testing results are below.
Testing Environment:
Hardware: Romley-EP platform
Xen version: latest upstream
Linux kernel: 3.4-RC6
Guest vCPU number: 8
NIC: Intel 82599 (10GB bandwidth)
In 'kernel build' testing in guest:
Command line | performance gain
make -j 4 | 3.81%
make -j 8 | 0.37%
make -j 16 | -0.52%
In 'netperf' testing, we tested TCP_STREAM with default socket size
16384 byte as large packet and 64 byte as small packet.
I used several clients to add networking pressure, then 'netperf' server
automatically generated several threads to response them.
I also used large-size packet and small-size packet in the testing.
Packet size | Thread number | performance gain
16384 bytes | 4 | 0.02%
16384 bytes | 8 | 2.21%
16384 bytes | 16 | 2.04%
64 bytes | 4 | 1.07%
64 bytes | 8 | 3.31%
64 bytes | 16 | 0.71%
Signed-off-by: Alex Shi <alex.shi@intel.com>
Link: http://lkml.kernel.org/r/1340845344-27557-8-git-send-email-alex.shi@intel.com
Tested-by: Ren, Yongjie <yongjie.ren@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
x86 has no flush_tlb_range support in instruction level. Currently the flush_tlb_range just implemented by flushing all page table. That is not the best solution for all scenarios. In fact, if we just use 'invlpg' to flush few lines from TLB, we can get the performance gain from later remain TLB lines accessing. But the 'invlpg' instruction costs much of time. Its execution time can compete with cr3 rewriting, and even a bit more on SNB CPU. So, on a 512 4KB TLB entries CPU, the balance points is at: (512 - X) * 100ns(assumed TLB refill cost) = X(TLB flush entries) * 100ns(assumed invlpg cost) Here, X is 256, that is 1/2 of 512 entries. But with the mysterious CPU pre-fetcher and page miss handler Unit, the assumed TLB refill cost is far lower then 100ns in sequential access. And 2 HT siblings in one core makes the memory access more faster if they are accessing the same memory. So, in the patch, I just do the change when the target entries is less than 1/16 of whole active tlb entries. Actually, I have no data support for the percentage '1/16', so any suggestions are welcomed. As to hugetlb, guess due to smaller page table, and smaller active TLB entries, I didn't see benefit via my benchmark, so no optimizing now. My micro benchmark show in ideal scenarios, the performance improves 70 percent in reading. And in worst scenario, the reading/writing performance is similar with unpatched 3.4-rc4 kernel. Here is the reading data on my 2P * 4cores *HT NHM EP machine, with THP 'always': multi thread testing, '-t' paramter is thread number: with patch unpatched 3.4-rc4 ./mprotect -t 1 14ns 24ns ./mprotect -t 2 13ns 22ns ./mprotect -t 4 12ns 19ns ./mprotect -t 8 14ns 16ns ./mprotect -t 16 28ns 26ns ./mprotect -t 32 54ns 51ns ./mprotect -t 128 200ns 199ns Single process with sequencial flushing and memory accessing: with patch unpatched 3.4-rc4 ./mprotect 7ns 11ns ./mprotect -p 4096 -l 8 -n 10240 21ns 21ns [ hpa: http://lkml.kernel.org/r/1B4B44D9196EFF41AE41FDA404FC0A100BFF94@SHSMSX101.ccr.corp.intel.com has additional performance numbers. ] Signed-off-by: Alex Shi <alex.shi@intel.com> Link: http://lkml.kernel.org/r/1340845344-27557-3-git-send-email-alex.shi@intel.com Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Pull x86 mm changes from Ingo Molnar: "This tree includes a micro-optimization that avoids cr3 switches during idling; it fixes corner cases and there's also small cleanups" Fix up trivial context conflict with the percpu_xx -> this_cpu_xx changes. * 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86-64: Fix accounting in kernel_physical_mapping_init() x86/tlb: Clean up and unify TLB_FLUSH_ALL definition x86: Drop obsolete ARCH_BOOTMEM support x86, tlb: Switch cr3 in leave_mm() only when needed x86/mm: Fix the size calculation of mapping tables
Since sizeof(long) is 4 in x86_32 mode, and it's 8 in x86_64 mode, sizeof(long long) is also 8 byte in x86_64 mode. use long mode can fit TLB_FLUSH_ALL defination here both in 32 or 64 bits mode. Signed-off-by: Alex Shi <alex.shi@intel.com> Link: http://lkml.kernel.org/n/tip-evv5bekiipi2pmyzdsy8lkkw@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Since percpu_xxx() serial functions are duplicated with this_cpu_xxx(). Removing percpu_xxx() definition and replacing them by this_cpu_xxx() in code. There is no function change in this patch, just preparation for later percpu_xxx serial function removing. On x86 machine the this_cpu_xxx() serial functions are same as __this_cpu_xxx() without no unnecessary premmpt enable/disable. Thanks for Stephen Rothwell, he found and fixed a i386 build error in the patch. Also thanks for Andrew Morton, he kept updating the patchset in Linus' tree. Signed-off-by: Alex Shi <alex.shi@intel.com> Acked-by: Christoph Lameter <cl@gentwo.org> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Tejun Heo <tj@kernel.org>