Re: [PATCH v2] mm: vmalloc: Clean up vunmap to avoid pgtable ops twice

2018-04-30 Thread Chintan Pandya
On 5/1/2018 4:22 AM, Andrew Morton wrote: On Mon, 16 Apr 2018 16:29:02 +0530 Chintan Pandya wrote: vunmap does page table clear operations twice in the case when DEBUG_PAGEALLOC_ENABLE_DEFAULT is enabled. So, clean up the code as that is unintended. As a perf gain, we save few us. Below f

Re: [PATCH v2] mm: vmalloc: Clean up vunmap to avoid pgtable ops twice

2018-04-30 Thread Andrew Morton
On Mon, 16 Apr 2018 16:29:02 +0530 Chintan Pandya wrote: > vunmap does page table clear operations twice in the > case when DEBUG_PAGEALLOC_ENABLE_DEFAULT is enabled. > > So, clean up the code as that is unintended. > > As a perf gain, we save few us. Below ftrace data was > obtained while doi

[PATCH v2] mm: vmalloc: Clean up vunmap to avoid pgtable ops twice

2018-04-16 Thread Chintan Pandya
vunmap does page table clear operations twice in the case when DEBUG_PAGEALLOC_ENABLE_DEFAULT is enabled. So, clean up the code as that is unintended. As a perf gain, we save few us. Below ftrace data was obtained while doing 1 MB of vmalloc/vfree on ARM64 based SoC *without* this patch applied.