From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 6645D3858D1E; Mon, 20 May 2024 20:05:43 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 6645D3858D1E DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1716235543; bh=W76CUMRE8AbRhE3Z6ceYC7Yfkk8uWGvIjSpuN/oQFuo=; h=From:To:Subject:Date:In-Reply-To:References:From; b=mjobXppeDzbEgodR2+WatPeISGLxMZeUYfIibeMaxTmomBZS6zKzrjgL7dMJ1Wv0y eYEs/4wWCauNtoiS20IdVdRxyCOiuWCSyHNis7qO2iH8ahdwJI2xnGaMfmojCq9dsQ KM9fQLczD5ffHuppvuwk2mOifw+4pUTgZRUbjXoY= From: "thiago.bauermann at linaro dot org" To: gdb-prs@sourceware.org Subject: [Bug testsuite/31312] attach-many-short-lived-threads gives inconsistent results Date: Mon, 20 May 2024 20:05:42 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gdb X-Bugzilla-Component: testsuite X-Bugzilla-Version: HEAD X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: thiago.bauermann at linaro dot org X-Bugzilla-Status: REOPENED X-Bugzilla-Resolution: X-Bugzilla-Priority: P2 X-Bugzilla-Assigned-To: cel at linux dot ibm.com X-Bugzilla-Target-Milestone: 15.1 X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: http://sourceware.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 List-Id: https://sourceware.org/bugzilla/show_bug.cgi?id=3D31312 --- Comment #40 from Thiago Jung Bauermann --- (In reply to Carl E Love from comment #37) > +FAIL: gdb.threads/attach-many-short-lived-threads.exp: iter 10: break at > break_fn: 1 (the program is no longer running) As I mentioned in comments 19 and 23, attach-many-short-lived-threads.exp exposed three problems in aarch64-linux-gnu and powerpc64le-linux-gnu. I proposed that we use this bugzilla to track the issue of GDB hanging with 100% CPU use because it wasn't able to deal with zombie threads. This is the problem I described in comment 17 and fixed in the patch series that I committed. This bug would appear in gdb.sum as timeout failures, because GDB would be effectively hung and DejaGNU wouldn't be able to communicate with = it anymore. So the FAIL messages above would indicate a different kind of prob= lem. A separate issue I described there was GDB thinking that it had found all inferior threads, and leaving the breakpoint instructions in the inferior w= hile inferior threads unknown to it were still running. This would cause the inferior to exit with a SIGTRAP as it hit those unexpected breakpoint instructions. The FAIL message above is consistent with this bug, which as = Tom de Vries mentioned is tracked in PR26286. We would need gdb.log to confirm whether it is really this problem that is happening. So if one accepts my suggestion of using this PR to track the problem of GDB entering an infinite loop in the presence of zombie inferior threads, then based on the gdb.sum that Carl posted I'd argue that there's no evidence th= at it's still happening. --=20 You are receiving this mail because: You are on the CC list for the bug.=