From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jens Axboe Date: Fri, 01 Jan 2021 15:35:40 +0000 Subject: Re: [PATCH] sh: add support for TIF_NOTIFY_SIGNAL Message-Id: <10752e73-ca2a-9ea7-4aa6-35e366e36fb0@kernel.dk> List-Id: References: <5fcc82b4-89ae-3bca-10ab-6ad933565cee@kernel.dk> <5611bde9-67e7-6ff6-defc-9b02ea830fac@physik.fu-berlin.de> <9ea14eb3-d698-5499-ba4c-c6a3c35cd8d4@kernel.dk> <47f79645-53b7-b11c-167a-f5721b53df02@physik.fu-berlin.de> <9d9acec6-1e8c-2d68-5dfa-d58c11cf5cc4@kernel.dk> <070780c4-445e-6373-c8f4-1c72d0f3b4e0@physik.fu-berlin.de> <1047f3e5-4599-c34f-3176-9f41d2e1246b@kernel.dk> <31b34cfc-8d6e-d3b4-e29f-1ec485f5b368@physik.fu-berlin.de> <23bf4423-0987-c445-d5cd-1922e1e40820@kernel.dk> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: John Paul Adrian Glaubitz Cc: linux-sh@vger.kernel.org, "linux-ia64@vger.kernel.org" On 1/1/21 8:30 AM, John Paul Adrian Glaubitz wrote: > Hi Jens! > > On 1/1/21 4:08 PM, Jens Axboe wrote: >> On 1/1/21 7:06 AM, John Paul Adrian Glaubitz wrote: >>> Is there away to test the change itself? >> >> The only user of TWA_SIGNAL, which uses TIF_NOTIFY_SIGNAL, so far is io_uring. >> You need something that triggers deferred task_work processing, which is >> basically anything that ends up being poll driven for data/space readiness. >> Here's a small test app from the liburing test suite, that'll trigger it. >> >> If you install liburing, compile with: >> >> gcc -Wall -O2 -o socket-rw socket-rw.c -luring >> >> and run it without any arguments. > > How long is this test supposed to run? It's already been running for some minutes > on my 600 MHz machine. It's supposed to finish very quickly: axboe@p1 ~> time ./socket-rw 0.000s ________________________________________________________ Executed in 1.10 millis fish external usr time 888.00 micros 278.00 micros 610.00 micros sys time 35.00 micros 35.00 micros 0.00 micros If it doesn't, can you try: # echo 1 > /sys/kernel/debug/tracing/events/io_uring/enable Then run the socket-rw app, and then do: # cat /sys/kernel/debug/tracing/trace and send that output? Might also be useful to include the strace of the socket-rw just in case, so maybe run it ala strace -o foo ./socket-rw and include foo in the reply as well. -- Jens Axboe