[PATCH 3/4] ARC: perf: avoid vmalloc backed mmap

For non-alising Dcache, vmalloc is not needed. vmalloc triggers additonal D-TLB Misses in the perf interrupt code path making it slightly inefficient as evident from hackbench runs below. | [ARCLinux]# perf stat -e dTLB-load-misses --repeat 5 hackbench | Running with 10*40 (== 400) tasks. | Time:

[PATCH 4/4] ARCv2: entry: Reduce perf intr return path

In the more likely case of returning to kernel from perf interrupt, do a fast path returning w/o bothering about CONFIG_PREEMPT etc However, if returning to user space, need do go thru the usual gyrations, as check for pending signals is an absolute must. Signed-off-by: Vineet Gupta --- arch/ar

[PATCH 2/4] ARCv2: perf: optimize given that num counters <= 32

use ffz primitive which maps to ARCv2 instruction, vs. non atomic __test_and_set_bit It is unlikely if we will even have more than 32 counters, but still add a BUILD_BUG to catch that Signed-off-by: Vineet Gupta --- arch/arc/kernel/perf_event.c | 16 +++- 1 file changed, 7 insertion

[PATCH 0/4] ARC perf updates

Hi, Found these when cleaning up some old branches. The only controversial one could be the last one. Thx, -Vineet Vineet Gupta (4): ARCv2: perf: tweak overflow interrupt ARCv2: perf: optimize given that num counters <= 32 ARC: perf: avoid vmalloc backed mmap ARCv2: entry: Reduce perf in

[PATCH 1/4] ARCv2: perf: tweak overflow interrupt

Current perf ISR loops thru all 32 counters, checking for each if it caused the interrupt. Instead only loop thru counters which actually interrupted (typically 1). Signed-off-by: Vineet Gupta --- arch/arc/kernel/perf_event.c | 24 ++-- 1 file changed, 14 insertions(+), 10 de

Re: [PATCH] ARCv2: Accomodate NS48 MMUv5 by releaxing MMU ver checking

On 11/07/2017 07:33 AM, Alexey Brodkin wrote: Hi Vineet, Subject contains one typo: NS48 -> HS48. On Mon, 2017-11-06 at 11:30 -0800, Vineet Gupta wrote: HS48 cpus will have a new MMUv5, although Linux is currently not explicitly supporting the newer features (so remains at V4). The existing so

Re: [PATCH] ARCv2: Accomodate NS48 MMUv5 by releaxing MMU ver checking

Hi Vineet, Subject contains one typo: NS48 -> HS48. On Mon, 2017-11-06 at 11:30 -0800, Vineet Gupta wrote: > > HS48 cpus will have a new MMUv5, although Linux is currently not > explicitly supporting the newer features (so remains at V4). > The existing software/hardware version check is very ti

Re: [PATCH v2 2/2] console: don't select first registered console if stdout-path used

Hi Eigeniy, I am sorry for the late response. The problem is far from trivial. I am getting snowed under many other tasks as well. On Wed 2017-09-06 17:57:18, Eugeniy Paltsev wrote: > Hi Petr, > > On Tue, 2017-09-05 at 16:54 +0200, Petr Mladek wrote: > > On Mon 2017-08-28 19:58:07, Eugeniy Palt