From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mout.kundenserver.de (mout.kundenserver.de [212.227.126.133]) by sourceware.org (Postfix) with ESMTPS id 34C4E384BC22 for ; Thu, 9 Sep 2021 09:37:08 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 34C4E384BC22 Authentication-Results: sourceware.org; dmarc=fail (p=none dis=none) header.from=cygwin.com Authentication-Results: sourceware.org; spf=fail smtp.mailfrom=cygwin.com Received: from calimero.vinschen.de ([24.134.7.25]) by mrelayeu.kundenserver.de (mreue009 [212.227.15.167]) with ESMTPSA (Nemesis) id 1N0G5n-1nBoFJ2aDn-00xKH1 for ; Thu, 09 Sep 2021 11:37:06 +0200 Received: by calimero.vinschen.de (Postfix, from userid 500) id 0EBA3A80D3D; Thu, 9 Sep 2021 11:37:06 +0200 (CEST) Date: Thu, 9 Sep 2021 11:37:06 +0200 From: Corinna Vinschen To: cygwin-developers@cygwin.com Subject: Re: cygrunsrv + sshd + rsync = 20 times too slow -- throttled? Message-ID: Reply-To: cygwin-developers@cygwin.com Mail-Followup-To: cygwin-developers@cygwin.com References: <20210907195023.31ad8194457bb90c2b6971b4@nifty.ne.jp> <20210908090748.3e70ed5aea3fa3c320b5ae0d@nifty.ne.jp> <20210908131141.bf63a795ce13c8dd8f5c13a8@nifty.ne.jp> <20210908184511.75c901b132c71911aaaa6ad6@nifty.ne.jp> <20210908194529.148fe98ca7593b079d0b1e65@nifty.ne.jp> <20210909122141.ad3fb87c03395a59d961fc3d@nifty.ne.jp> MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="xWC5uW01as1/wn0N" Content-Disposition: inline In-Reply-To: <20210909122141.ad3fb87c03395a59d961fc3d@nifty.ne.jp> X-Provags-ID: V03:K1:VxOvysk8861LPS729viR84Fw5JmF59b6KJAiKFy658N9adnAyWp 5fiH4MqQ6wnJNiojibl4+QZYVj0T6ZvbWcvh6cNBJwp2Ssc8V2wrkQ8sHw5i1L60X38FJtT pv/G7JHBBVsNqezvKZbXNqiefu686tlz29BGoJOR2PC4MJs5RiNG+DqMOYhEgUEh6/Ujl4I AhHVBN3MEFEhjiUUAZ6aw== X-UI-Out-Filterresults: notjunk:1;V03:K0:RQOOHRDPlvM=:82hYDPz1EkzQqlkJzjcdId DyA7+9UKzR4DHUt7v64ob7vXOUov/bCMF21OuXogcUgHiFjiCtiY0V7ctwAOXqzUczwSI6x/h gWOKNaGZamARmFOSVL/M6zSeFgMbfWUu+6X0eSKG0Ua4WXclYpFGc01ZowZBqyTLqwOM/QCDv foubqge5jFkaexLxfH2DjDCND+SnvES1E+4ANk4Eiz9gF80We3nYUE4Qm6xB/pJKs/sifGGjO Odj6BCZKBSNq0lVwr+n1VCUGov+BZwBbNPvbZk52Gwsf9rP4eitQ8c7SOZ8G0f4hwvTemrVZ8 NklsTahvreGL51q2s/naqqoIv+EfH42MizMIWa8lNtiOKA2d5lOE+fDkHU3xAU1MBiYgHJBaM YdQrExZjO6gdwA+L1ZQ3tPMa4fLc9sYaE6Ubo+N/dw3UFB9eCzoq2NPXnTxuSYiQ5BpwnhTkd 6KU5BOy6r4JsN21cLxkqjxHebRDr2zHKv6Lz+xN1Zv9p0dF8xjI99fEB5BKzCQodlpiXPdBjf VxOb0clNgeK+KjneGo7Qc/8j20lHmYb7/0W23cHeDHegKvcmy257YyqHh/PuSppd0XIifH4bw ahM6QAPUdWIcZXA/+MFMgPhlak3sc0UzA0xGk1bJxailRaFb8TGz87C0D06BUT165QnecRNgb sATcFypw4++zvh0b4G+3F/3pl9WqdK+9WYRo9Rp01Pq5WXfx3xLakYR0qbuSVVQSFQnzwBC8v 7CIlO8F1mPm1rtCjmvBzL7A7+r9v5t/sXYNwW7WxMkBjZfrk7lXwDxc+qYI= X-Spam-Status: No, score=-106.0 required=5.0 tests=BAYES_00, GIT_PATCH_0, GOOD_FROM_CORINNA_CYGWIN, KAM_DMARC_NONE, KAM_DMARC_STATUS, RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H4, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_NEUTRAL, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: cygwin-developers@cygwin.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: Cygwin core component developers mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 09 Sep 2021 09:37:09 -0000 --xWC5uW01as1/wn0N Content-Type: text/plain; charset=utf-8 Content-Disposition: inline On Sep 9 12:21, Takashi Yano wrote: > On Wed, 8 Sep 2021 12:51:31 +0200 > Corinna Vinschen wrote: > > > > Just one question. Would you mind to split your patch into two parts, > > > > one being just the revert of your "Improve select/poll response." patch > > > > and one introducing select_sem? > > > > > > I split the patch as you advised. > > > > Pushed. > > Timing of select_sem notification is fixed by the patch attached. If I'm not entirely off-track, I think this isn't quite right yet. I assume you want to release the semaphore in all cases some bytes have been read or written, right? If so, this should cover the STATUS_THREAD_CANCELED and STATUS_BUFFER_OVERFLOW cases as well. But then again, the ReleaseSemaphore calls are a bit spread out over the calls. I took the liberty to create a followup patch to the attached one. It merges all cases potentially reading or writing some bytes into a single if branch, so only a single ReleaseSemaphore should be required. I dropped STATUS_MORE_ENTRIES because it's not an error, subsumed under NT_SUCCESS, and IIUC, never emitted by the underlying code. I attached the patch to this mail, can you please check it? Thanks, Corinna --xWC5uW01as1/wn0N Content-Type: text/patch; charset=utf-8 Content-Disposition: attachment; filename="0001-Cygwin-pipes-always-signal-select_sem-if-any-bytes-a.patch" >From 11bea88b788aabb762b4e972a7f3fb2423fb32d8 Mon Sep 17 00:00:00 2001 From: Corinna Vinschen Date: Thu, 9 Sep 2021 11:35:54 +0200 Subject: [PATCH] Cygwin: pipes: always signal select_sem if any bytes are read or written Fold all code branches potentially having read or written data into a single if branch, so signalling select_sem catches all cases. Signed-off-by: Corinna Vinschen --- winsup/cygwin/fhandler_pipe.cc | 64 ++++++++++++---------------------- 1 file changed, 23 insertions(+), 41 deletions(-) diff --git a/winsup/cygwin/fhandler_pipe.cc b/winsup/cygwin/fhandler_pipe.cc index 488e14be8c2b..6994a5dceb84 100644 --- a/winsup/cygwin/fhandler_pipe.cc +++ b/winsup/cygwin/fhandler_pipe.cc @@ -303,20 +303,11 @@ fhandler_pipe::raw_read (void *ptr, size_t& len) waitret = WAIT_OBJECT_0; if (waitret == WAIT_CANCELED) - { - status = STATUS_THREAD_CANCELED; - break; - } + status = STATUS_THREAD_CANCELED; else if (waitret == WAIT_SIGNALED) - { - status = STATUS_THREAD_SIGNALED; - nbytes += io.Information; - if (select_sem && io.Information > 0) - ReleaseSemaphore (select_sem, - get_obj_handle_count (select_sem), NULL); - break; - } - status = io.Status; + status = STATUS_THREAD_SIGNALED; + else + status = io.Status; } if (isclosed ()) /* A signal handler might have closed the fd. */ { @@ -326,11 +317,17 @@ fhandler_pipe::raw_read (void *ptr, size_t& len) __seterrno (); nbytes = (size_t) -1; } - else if (NT_SUCCESS (status)) + else if (NT_SUCCESS (status) + || status == STATUS_BUFFER_OVERFLOW + || status == STATUS_THREAD_CANCELED + || status == STATUS_THREAD_SIGNALED) { nbytes_now = io.Information; ptr = ((char *) ptr) + nbytes_now; nbytes += nbytes_now; + if (select_sem && nbytes_now > 0) + ReleaseSemaphore (select_sem, + get_obj_handle_count (select_sem), NULL); } else { @@ -341,13 +338,6 @@ fhandler_pipe::raw_read (void *ptr, size_t& len) case STATUS_PIPE_BROKEN: /* This is really EOF. */ break; - case STATUS_MORE_ENTRIES: - case STATUS_BUFFER_OVERFLOW: - /* `io.Information' is supposedly valid. */ - nbytes_now = io.Information; - ptr = ((char *) ptr) + nbytes_now; - nbytes += nbytes_now; - break; case STATUS_PIPE_LISTENING: case STATUS_PIPE_EMPTY: if (nbytes != 0) @@ -366,10 +356,8 @@ fhandler_pipe::raw_read (void *ptr, size_t& len) } } - if (nbytes_now == 0) + if (nbytes_now == 0 || status == STATUS_BUFFER_OVERFLOW) break; - else if (select_sem) - ReleaseSemaphore (select_sem, get_obj_handle_count (select_sem), NULL); } ReleaseMutex (read_mtx); if (evt) @@ -467,20 +455,11 @@ fhandler_pipe_fifo::raw_write (const void *ptr, size_t len) waitret = WAIT_OBJECT_0; if (waitret == WAIT_CANCELED) - { - status = STATUS_THREAD_CANCELED; - break; - } + status = STATUS_THREAD_CANCELED; else if (waitret == WAIT_SIGNALED) - { - status = STATUS_THREAD_SIGNALED; - nbytes += io.Information; - if (select_sem && io.Information > 0) - ReleaseSemaphore (select_sem, - get_obj_handle_count (select_sem), NULL); - break; - } - status = io.Status; + status = STATUS_THREAD_SIGNALED; + else + status = io.Status; } if (isclosed ()) /* A signal handler might have closed the fd. */ { @@ -489,13 +468,18 @@ fhandler_pipe_fifo::raw_write (const void *ptr, size_t len) else __seterrno (); } - else if (NT_SUCCESS (status)) + else if (NT_SUCCESS (status) + || status == STATUS_THREAD_CANCELED + || status == STATUS_THREAD_SIGNALED) { nbytes_now = io.Information; ptr = ((char *) ptr) + nbytes_now; nbytes += nbytes_now; + if (select_sem && nbytes_now > 0) + ReleaseSemaphore (select_sem, + get_obj_handle_count (select_sem), NULL); /* 0 bytes returned? EAGAIN. See above. */ - if (nbytes == 0) + if (NT_SUCCESS (status) && nbytes == 0) set_errno (EAGAIN); } else if (STATUS_PIPE_IS_CLOSED (status)) @@ -508,8 +492,6 @@ fhandler_pipe_fifo::raw_write (const void *ptr, size_t len) if (nbytes_now == 0) break; - else if (select_sem) - ReleaseSemaphore (select_sem, get_obj_handle_count (select_sem), NULL); } if (evt) CloseHandle (evt); -- 2.31.1 --xWC5uW01as1/wn0N--