From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0F3B1C77B73 for ; Tue, 2 May 2023 20:12:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229887AbjEBUMd (ORCPT ); Tue, 2 May 2023 16:12:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45244 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229605AbjEBUMb (ORCPT ); Tue, 2 May 2023 16:12:31 -0400 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2C5AC10FF for ; Tue, 2 May 2023 13:12:30 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id 3f1490d57ef6-b9e50081556so3379097276.3 for ; Tue, 02 May 2023 13:12:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1683058349; x=1685650349; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=PxtEaaNRJEnS8gUq7TvU2r4SfUgelfPOgo5JiP3hUpo=; b=BYEMeUVTavoTcRxgokm9LZOiUo7JnHslNZEV71QJ15VCAvQjDYwvQHxDp2GbTG40ky jG2xF68/iZX42EldBxCWvGasW0z36zT9XC1HFjr04Y697ZGrsWbiwH2FA3zv1TtdktJI 55wsjAMD/JNIzadT0P2aX0LbJlXXDdBrpC+GmJBScI84NR/3vbTpABptoKLhg91pELnJ ZuB7VbtRpx+HBXi/6wB6WZLOPfNdjpWyFCMJQiN1NG7xXqLQAt3cQH0KBgMiTmqWaWDl TLaP3TxZgsfeHl6em2N7yxiTF+tiX72e521bm6Gb7UjxnkW8hG3L0ZbkQZOAvzPTQcE6 FxIA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1683058349; x=1685650349; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=PxtEaaNRJEnS8gUq7TvU2r4SfUgelfPOgo5JiP3hUpo=; b=gafNx7W/0x0SZ8/H7p4j0ljJFgvLYNvvJcc9K0xvOdQ5KYA6xtlwnIJKR3SluA2m+H fbEh7mtbQAMLy5dqZ9rC4kR2cm667ebEm5sMPrM8jQVSQJIJNV3sMlvYj6FUVpxlG/ky 5HQP6cuY7a1mLt7LRlMMIV2MSaCYnzDbcl0LiLIgASkgaBgQSs12T+Y58MFxSJs4JILJ s8rPQ+Jit4ZhBr6voGrKwNSEVqe0U9qbsi3CPbTkqt7Ci7ecww13DapMBleIRD6M/hoJ BYIL12r/sjo7/S6uWRGfNsQUFGIgcApSF/rRX9Cnsiy/Vj5g2VSDCWPUIvlcimdvBktw k1OQ== X-Gm-Message-State: AC+VfDy6OSklRFCSpfGoga0jxejiGg2CrLxNkONzmNhfIx2/j37tmfUh qJMwSV97wXPKjByP4gKU+AAgdpC6+tomUQ== X-Google-Smtp-Source: ACHHUZ71vmhsscaNHlobIISSRxVBPUvmF6vJFmZpp0ShentSMNd8RVevcFg864koEGGNqYEDfNo3/RpT+CLYXQ== X-Received: from xllamas.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5070]) (user=cmllamas job=sendgmr) by 2002:a25:adcf:0:b0:b9d:894f:c9a8 with SMTP id d15-20020a25adcf000000b00b9d894fc9a8mr5202420ybe.0.1683058349442; Tue, 02 May 2023 13:12:29 -0700 (PDT) Date: Tue, 2 May 2023 20:12:17 +0000 Mime-Version: 1.0 X-Mailer: git-send-email 2.40.1.495.gc816e09b53d-goog Message-ID: <20230502201220.1756319-1-cmllamas@google.com> Subject: [PATCH 1/3] Revert "binder_alloc: add missing mmap_lock calls when using the VMA" From: Carlos Llamas To: Greg Kroah-Hartman , "=?UTF-8?q?Arve=20Hj=C3=B8nnev=C3=A5g?=" , Todd Kjos , Martijn Coenen , Joel Fernandes , Christian Brauner , Carlos Llamas , Suren Baghdasaryan , Andrew Morton , Liam Howlett Cc: linux-kernel@vger.kernel.org, kernel-team@android.com, stable@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This reverts commit 44e602b4e52f70f04620bbbf4fe46ecb40170bde. This caused a performance regression particularly when pages are getting reclaimed. We don't need to acquire the mmap_lock to determine when the binder buffer has been fully initialized. A subsequent patch will bring back the lockless approach for this. [cmllamas: resolved trivial conflicts with renaming of alloc->mm] Fixes: 44e602b4e52f ("binder_alloc: add missing mmap_lock calls when using the VMA") Cc: Liam Howlett Cc: Suren Baghdasaryan Cc: stable@vger.kernel.org Signed-off-by: Carlos Llamas --- drivers/android/binder_alloc.c | 31 ++++++++++--------------------- 1 file changed, 10 insertions(+), 21 deletions(-) diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c index 55a3c3c2409f..92c814ec44fe 100644 --- a/drivers/android/binder_alloc.c +++ b/drivers/android/binder_alloc.c @@ -380,15 +380,12 @@ static struct binder_buffer *binder_alloc_new_buf_locked( size_t size, data_offsets_size; int ret; - mmap_read_lock(alloc->mm); if (!binder_alloc_get_vma(alloc)) { - mmap_read_unlock(alloc->mm); binder_alloc_debug(BINDER_DEBUG_USER_ERROR, "%d: binder_alloc_buf, no vma\n", alloc->pid); return ERR_PTR(-ESRCH); } - mmap_read_unlock(alloc->mm); data_offsets_size = ALIGN(data_size, sizeof(void *)) + ALIGN(offsets_size, sizeof(void *)); @@ -916,25 +913,17 @@ void binder_alloc_print_pages(struct seq_file *m, * Make sure the binder_alloc is fully initialized, otherwise we might * read inconsistent state. */ - - mmap_read_lock(alloc->mm); - if (binder_alloc_get_vma(alloc) == NULL) { - mmap_read_unlock(alloc->mm); - goto uninitialized; - } - - mmap_read_unlock(alloc->mm); - for (i = 0; i < alloc->buffer_size / PAGE_SIZE; i++) { - page = &alloc->pages[i]; - if (!page->page_ptr) - free++; - else if (list_empty(&page->lru)) - active++; - else - lru++; + if (binder_alloc_get_vma(alloc) != NULL) { + for (i = 0; i < alloc->buffer_size / PAGE_SIZE; i++) { + page = &alloc->pages[i]; + if (!page->page_ptr) + free++; + else if (list_empty(&page->lru)) + active++; + else + lru++; + } } - -uninitialized: mutex_unlock(&alloc->mutex); seq_printf(m, " pages: %d:%d:%d\n", active, lru, free); seq_printf(m, " pages high watermark: %zu\n", alloc->pages_high); -- 2.40.1.495.gc816e09b53d-goog