From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 638954174A; Wed, 13 Mar 2024 13:46:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710337610; cv=none; b=JPMb/ZNvxmYJcZ+iRS4B/w/4H05qWQXOdsVIIS9Q4bnk9WIEBI141U+m80F3bZ+QnWr3MCKbBFnZLeuHQnnZboYJPBaHKUZZz3I5ODmecEuzBBpLSxjSqPDuzvp/9AUdh/mfnNDvuTazN4zFstqlz5QzhdWkupG6iBa3Atv3YO4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710337610; c=relaxed/simple; bh=vIjAdfBoiWL33bZ0WTDYgYhPbH4wUcMAQ5Y8wEr1dZY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=tgviVFqb0d9VAcCnx6b64XHvSldqqPEUBW0CPegvcSuAeYhzfeTapOxPP+seGqFmEMI7y1z80R4nzfjaLHj2jRhirD1Rce681qNC0W8sjuyIVNX2kzE8KUzH0PtPy/MLVH8htWWsrcKsV01eRpQWHK6fvEbF+nkF/JJGUksiGi4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=J1KVgT+H; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=W1urmu50; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="J1KVgT+H"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="W1urmu50" Date: Wed, 13 Mar 2024 14:46:45 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1710337607; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=vIjAdfBoiWL33bZ0WTDYgYhPbH4wUcMAQ5Y8wEr1dZY=; b=J1KVgT+H/VBL8Agxtd3g3sdQEzrXIQCmmgC3w0ULmKRAro3/j4L9H3Gay8WHXFA7sIFsc9 L5Hdx7X3dY8JXM55fuYBhZfzR7xbh4agBFaLwpl7QRN+Q4E2K8YeHqlVfUV+03R3t+qO6I 3V0R6JXK/Vp+TecJ3zTb+hvR61wOZj/1BJ8FtJrkHRHjGWYsgbO3dXGN8F1QfuF3hR2L/M RyMv8SnSLCMKAQPpwdcKpzEnOt1T2stcSxy38finxf63UjMH07uYRIidk8dhPX78DgZSh4 Kl0Z89JWHMTUpylW+thitV5soAJqvgbndIila2qyVAny64jmK8XkIlMdihuvSA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1710337607; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=vIjAdfBoiWL33bZ0WTDYgYhPbH4wUcMAQ5Y8wEr1dZY=; b=W1urmu50u6l/cXHFtJauFiPDwtDppplz/TQaBN0m9x4jLBK3dO38RFJgZ4cBxIZe96oMHQ Pxbw7Fs0NUgpCVBQ== From: Sebastian Andrzej Siewior To: Arnaldo Carvalho de Melo Cc: linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, Adrian Hunter , Alexander Shishkin , Ian Rogers , Ingo Molnar , Jiri Olsa , Marco Elver , Mark Rutland , Namhyung Kim , Peter Zijlstra , Thomas Gleixner Subject: Re: [PATCH v2 0/4] perf: Make SIGTRAP and __perf_pending_irq() work on RT. Message-ID: <20240313134645.bO-XyxAM@linutronix.de> References: <20240312180814.3373778-1-bigeasy@linutronix.de> <20240313081303.DClwQrvb@linutronix.de> Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable In-Reply-To: On 2024-03-13 10:28:41 [-0300], Arnaldo Carvalho de Melo wrote: > > One part I don't get: did you let it run or did you kill it? >=20 > If I let them run they will finish and exit, no exec_child remains. >=20 > If I instead try to stop the loop that goes on forking the 100 of them, > then the exec_child remain spinning. Okay. So that problem only exists if you intervene. And you can reproduce this odd behaviour with my patches but not without them, right? > > it shouldn't remain there for ever. And my guess, that it is in spinning > > in userland and not in kernel. >=20 > Checking that now, the stack is the one I posted: >=20 > > > [root@nine ~]# cat /proc/24263/stack > > > [<0>] irqentry_exit_to_user_mode+0x1c9/0x1e0 > > > [<0>] asm_sysvec_apic_timer_interrupt+0x16/0x20 > > > [root@nine ~]# could you resolve irqentry_exit_to_user_mode+0x1c9/0x1e0, please? > > I tried it on bare metal and VM and couldn't reproduce this. >=20 > All my tests are in bare metal. Would you mind sending me your .config? The shell is bash I guess. I will try to reproduce your setup on another box=E2=80=A6 > - Arnaldo Sebastian