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Wed, 05 Jun 2024 16:14:59 -0700 (PDT) Message-ID: Date: Wed, 5 Jun 2024 16:14:56 -0700 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: linux-user emulation hangs during fork To: Andreas Schwab , qemu-devel@nongnu.org References: Content-Language: en-US From: Richard Henderson In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=2607:f8b0:4864:20::62b; envelope-from=richard.henderson@linaro.org; helo=mail-pl1-x62b.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On 6/5/24 02:14, Andreas Schwab wrote: > $ qemu-x86_64 --version > qemu-x86_64 version 9.0.50 (v9.0.0-1211-gd16cab541a) > Copyright (c) 2003-2024 Fabrice Bellard and the QEMU Project developers > $ cat fork.rb > begin > r, w = IO.pipe > if pid1 = fork > w.close > r.read 1 > Process.kill "USR1", pid1 > Process.wait2 pid1 > else > print "child\n" > r.close > if pid2 = fork > trap("USR1") { print "child: kill\n"; Process.kill "USR2", pid2 } > w.close > print "child: wait\n" > Process.wait2 pid2 > else > print "grandchild\n" > w.close > sleep 0.2 > end > end > end > $ ruby fork.rb > child > child: wait > grandchild > child: kill > $ qemu-x86_64 /usr/bin/ruby fork.rb > child > child: wait > ^Z > [1]+ Stopped qemu-x86_64 /usr/bin/ruby fork.rb > $ grep SigB $(for p in $(pidof qemu-x86_64); do echo /proc/$p/status; done | sort) > /proc/3221/status:SigBlk: 0000000000000000 > /proc/3224/status:SigBlk: 0000000000000000 > /proc/3228/status:SigBlk: fffffff27ffbfa9f > Works for me: rth@stoup:~/zz$ ~/qemu/bld/qemu-x86_64 `which ruby` fork.rb child grandchild child: wait child: kill rth@stoup:~/zz$ ~/qemu/bld/qemu-x86_64 `which ruby` fork.rb child grandchild child: wait child: kill rth@stoup:~/zz$ ~/qemu/bld/qemu-x86_64 `which ruby` fork.rb child grandchild child: wait child: kill rth@stoup:~/zz$ ~/qemu/bld/qemu-x86_64 `which ruby` fork.rb child grandchild child: wait child: kill r~