(updated Pasha's e-mail) Thu, Sep 13, 2018 at 01:35:20PM +0300, Timofey Titovets wrote: > пн, 25 июн. 2018 г. в 11:48, Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx>: > > > > On Thu, Jun 07, 2018 at 09:29:49PM -0400, Pavel Tatashin wrote: > > > > With CONFIG_SYSFS=n there is nothing that will set ksm_run to anything but > > > > zero and ksm_do_scan will never be called. > > > > > > > > > > Unfortunatly, this is not so: > > > > > > In: /linux-master/mm/ksm.c > > > > > > 3143#else > > > 3144 ksm_run = KSM_RUN_MERGE; /* no way for user to start it */ > > > 3145 > > > 3146#endif /* CONFIG_SYSFS */ > > > > > > So, we do set ksm_run to run right from ksm_init() when CONFIG_SYSFS=n. > > > > > > I wonder if this is acceptible to only use xxhash when CONFIG_SYSFS=n ? > > > > BTW, with CONFIG_SYSFS=n KSM may start running before hardware acceleration > > for crc32c is initialized... > > > > > Thank you, > > > Pavel > > > > > > > -- > > Sincerely yours, > > Mike. > > > > Little thread bump. > That patchset can't move forward already for about ~8 month. > As i see main question in thread: that we have a race with ksm > initialization and availability of crypto api. > Maybe we then can fall back to simple plan, and just replace old good > buddy jhash by just more fast xxhash? > That allow move question with crypto api & crc32 to background, and > make things better for now, in 2-3 times. > > What you all think about that? Sounds reasonable to me > > crc32c_intel: 1084.10ns > > crc32c (no hardware acceleration): 7012.51ns > > xxhash32: 2227.75ns > > xxhash64: 1413.16ns > > jhash2: 5128.30ns > > -- > Have a nice day, > Timofey. > -- Sincerely yours, Mike.
