Re: [linux-next:master] [memcg] 01d37228d3: netperf.Throughput_Mbps 37.9% regression

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 3/10/25 11:56, Alexei Starovoitov wrote:
> On Mon, Mar 10, 2025 at 11:34 AM Vlastimil Babka <vbabka@xxxxxxx> wrote:
>>
>> On 3/10/25 11:18, Alexei Starovoitov wrote:
>> >> because this will affect the refill even if consume_stock() fails not due to
>> >> a trylock failure (which should not be happening), but also just because the
>> >> stock was of a wrong memcg or depleted. So in the nowait context we deny the
>> >> refill even if we have the memory. Attached patch could be used to see if it
>> >> if fixes things. I'm not sure about the testcases where it doesn't look like
>> >> nowait context would be used though, let's see.
>> >
>> > Not quite.
>> > GFP_NOWAIT includes __GFP_KSWAPD_RECLAIM,
>> > so gfpflags_allow_spinning() will return true.
>>
>> Uh right, it's the new gfpflags_allow_spinning(), not the
>> gfpflags_allow_blocking() I'm used to and implicitly assumed, sorry.
>>
>> But then it's very simple because it has a bug:
>> gfpflags_allow_spinning() does
>>
>> return !(gfp_flags & __GFP_RECLAIM);
>>
>> should be !!
> 
> Ouch.
> So I accidentally exposed the whole linux-next to this stress testing
> of new trylock facilities :(
> But the silver lining is that this is the only thing that blew up :)
> Could you send a patch or I will do it later today.

OK
----8<----

[Index of Archives]     [Linux ARM Kernel]     [Linux ARM]     [Linux Omap]     [Fedora ARM]     [IETF Annouce]     [Bugtraq]     [Linux OMAP]     [Linux MIPS]     [eCos]     [Asterisk Internet PBX]     [Linux API]

  Powered by Linux