From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Mon, 03 May 2021 14:46:51 +0200 Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by lore.white.stw.pengutronix.de with esmtp (Exim 4.92) (envelope-from ) id 1ldXyN-0003DG-IP for lore@lore.pengutronix.de; Mon, 03 May 2021 14:46:51 +0200 Received: from desiato.infradead.org ([2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1ldXyM-0007UI-QY for lore@pengutronix.de; Mon, 03 May 2021 14:46:51 +0200 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=desiato.20200630; h=Sender:Content-Transfer-Encoding :Content-Type:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To:Message-Id:Date: Subject:Cc:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=4m3eITNYbxnrOUb3rBLCrx/dytUvKgDqMbK61HfMPqE=; b=A0U2YZdhqRpOznGEN13f1b4qe 0Noe4PYUh1utTrljjX1FPgzrqY+L7tE24LiHBEnwPWlmBnpC2qjnwQggWrneYn9BnkvQ3fPwl8kgM fTPyXUHO+B4RLE6bTWyliB5wO5/SGwHoyK19nU/6vTVhes34rW3kVPLqtTwImdARnOSK15CBlAs5P RG9VTuf4rUem/OZWB5P2dUDnTycWN+18d+CvkBlVYrHgHrXPRNnYoyyfn5MVSE/+iZ2H1id69Qwte A/8+I/vcCIxDVv51hXAFKSe8JsmwtieKyIR7fzio+ej0+3xZpn0xpPgvfXR55kcfBnckUBdUGptWg ZPSRByG2Q==; Received: from localhost ([::1] helo=desiato.infradead.org) by desiato.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1ldXxF-00DtDv-Tt; Mon, 03 May 2021 12:45:42 +0000 Received: from bombadil.infradead.org ([2607:7c80:54:e::133]) by desiato.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1ldXwu-00DtC6-7F for barebox@desiato.infradead.org; Mon, 03 May 2021 12:45:23 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=W06JT4EeD9hIS4K7+c/4712EyA4I3HTionXgUJUdByM=; b=WA6Zhzr7Q1WJ7MHiSC63omeofy KTSl3QChRQZkbi2Nticg/qAjonmMM9rneW+SehyiDG5W0V8QDxAvlBCgsHmtR83HXMFjTfQOMoIzO 8oCXQ4hUSmnX3Gn2zvHszAQZ+LP6oyAiViG4G92CIO8M+lv/raOUOchrpIgvktDmDe3mM6rAFoDpw Z3sQ4H9YOWkWKv/qzKSUvNtW2wJrnVIWHZjDxY7Rfwfl1Tkb9kudoNrUy/3qJXzTvAq+kZJA8fZIc WanzKRz7B7Ya/r7dMaM3M8aTryRz8lOJcgqOErJ7Lj4HmL6HBZN4aIf4bHzdI7ZZ47sLDJGP/JqRo NmROgBgQ==; Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1ldXwr-003417-Qp for barebox@lists.infradead.org; Mon, 03 May 2021 12:45:19 +0000 Received: from dude.hi.pengutronix.de ([2001:67c:670:100:1d::7]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1ldXwq-00072G-9x; Mon, 03 May 2021 14:45:16 +0200 Received: from afa by dude.hi.pengutronix.de with local (Exim 4.92) (envelope-from ) id 1ldXwp-0000Jy-Mi; Mon, 03 May 2021 14:45:15 +0200 From: Ahmad Fatoum To: barebox@lists.infradead.org Cc: Ahmad Fatoum Date: Mon, 3 May 2021 14:45:06 +0200 Message-Id: <20210503124508.856-3-a.fatoum@pengutronix.de> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210503124508.856-1-a.fatoum@pengutronix.de> References: <20210503124508.856-1-a.fatoum@pengutronix.de> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210503_054517_892147_C13115FA X-CRM114-Status: GOOD ( 12.44 ) X-BeenThere: barebox@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" X-SA-Exim-Connect-IP: 2001:8b0:10b:1:d65d:64ff:fe57:4e05 X-SA-Exim-Mail-From: barebox-bounces+lore=pengutronix.de@lists.infradead.org X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on metis.ext.pengutronix.de X-Spam-Level: X-Spam-Status: No, score=-3.6 required=4.0 tests=AWL,BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_NONE autolearn=unavailable autolearn_force=no version=3.4.2 Subject: [PATCH v3 2/4] slice: reschedule bthreads doing File I/O in command context X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on metis.ext.pengutronix.de) Currently, without locks, it's unsafe to do file I/O outside of the main thread, be it in pollers or secondary bthreads. Pollers side step this issue by deferring file I/O to workqueues that run in command context: the time when the shell is waiting for input. For bthreads, we can do something similar without involving workqueues: We just suspend threads until they are scheduled in command context. This is not a full solution: Not everything that should assert_command_context() does so, so you still can't do absolutely everything in a secondary bthread. To get there, we will need to distribute locks across the code base, but that's a patchset for another time. Signed-off-by: Ahmad Fatoum --- include/slice.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/include/slice.h b/include/slice.h index cf684300a809..abe819163d32 100644 --- a/include/slice.h +++ b/include/slice.h @@ -40,8 +40,10 @@ extern int poller_active; #define assert_command_context() do { \ WARN_ONCE(IS_ENABLED(CONFIG_POLLER) && poller_active, \ "%s called in poller\n", __func__); \ - WARN_ONCE(IS_ENABLED(CONFIG_BTHREAD) && !bthread_is_main(current), \ - "%s called in secondary bthread\n", __func__); \ + if (IS_ENABLED(CONFIG_BTHREAD) && !bthread_is_main(current)) { \ + while (slice_acquired(&command_slice)) \ + bthread_reschedule(); \ + } \ } while (0) #endif -- 2.29.2 _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox