From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.devel Subject: Re: igc, macOS avoiding signals Date: Sat, 28 Dec 2024 21:07:36 +0200 Message-ID: <861pxrsk1z.fsf@gnu.org> References: <799DDBC5-2C14-4476-B1E0-7BA2FE9E7901@toadstyle.org> <87ldvzg7vi.fsf@protonmail.com> <868qrzsojd.fsf@gnu.org> <87a5cffy8n.fsf@protonmail.com> <864j2nskup.fsf@gnu.org> Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="15287"; mail-complaints-to="usenet@ciao.gmane.io" Cc: spd@toadstyle.org, gerd.moellmann@gmail.com, emacs-devel@gnu.org To: pipcet@protonmail.com Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Sat Dec 28 20:08:35 2024 Return-path: Envelope-to: ged-emacs-devel@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1tRcAr-0003lo-Uk for ged-emacs-devel@m.gmane-mx.org; Sat, 28 Dec 2024 20:08:34 +0100 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tRcA4-00061f-Cn; Sat, 28 Dec 2024 14:07:46 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tRcA0-00061U-Qm for emacs-devel@gnu.org; Sat, 28 Dec 2024 14:07:41 -0500 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tRc9z-0007sn-Su; Sat, 28 Dec 2024 14:07:39 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=gnu.org; s=fencepost-gnu-org; h=References:Subject:In-Reply-To:To:From:Date: mime-version; bh=3FflsCh7TQmSeISfFjmxbuIV/FlFyThnRaNtUkp7xSo=; b=cL1nqQO2fDMg 59r1SXXhlnRMXT10ewK0dUYxTVsil8n+ku2ixgpwS8W5rwZIzct/ZjH6vjTiytSD1N/WAh6IXgZBW c2CLWwmH32SWjrdncyMjBTrM7T8i+3HFZDNzqCDubTrNR+HURvzv0EoGvcmtxNKj2gv5HNy/wzsnA ABGYaxLwTQnbocrtbUJurw8RN1/kwCR+V49aOR2jP40LYgamGjnXUj3TyTT8zC9bNm0ZoYurgEmEo GRDBquWr8dY3PsksIn/4Y3CnCi3IQpQruslBTPFIsqmJmI3L0zl59KwEsTxspujNm++q+6ct1BHuv H16H8xd/kfMQLX0/lJuZGA==; In-Reply-To: <864j2nskup.fsf@gnu.org> (message from Eli Zaretskii on Sat, 28 Dec 2024 20:50:22 +0200) X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.devel:327286 Archived-At: > Date: Sat, 28 Dec 2024 20:50:22 +0200 > From: Eli Zaretskii > Cc: spd@toadstyle.org, gerd.moellmann@gmail.com, emacs-devel@gnu.org > > > > What do we expect to learn from this, > > > > It tests the current code, which does this: > > > > When a signal arrives, and we can't handle it because we might have > > interrupted MPS, we mark the signal as pending in the igc structure. At > > some point later, we check the igc structure for pending signals, > > reraise them, and unmask them. > > > > Gerd's experience suggests that the "some point later" happens too late. > > This patch gives us measurements. > > > > It's unrelated to the OS scheduler, AFAICS. > > Ah, okay. I note that if we'd block signals when calling MPS and > unblock on exit, then these delays couldn't have happened, AFAIU. But OTOH, if this delaying of a signal affects responsiveness, then all we need to do is exempt SIGSEGV from being delayed, right? This signal-delay mechanism was invented for SIGPROF, SIGCHLD, and SIGALRM, but there's no reason to delay SIGSEGV. And AFAIU, on macOS there's no SIGSEGV anyway, is that right? So why does this delaying affect responsiveness? Or what am I missing?