From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B86DE5246 for ; Mon, 11 Dec 2023 00:55:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="NRn4dPTd" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 85D52C433C7; Mon, 11 Dec 2023 00:55:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1702256131; bh=3nUWAF0q25G6dMrSg9Uz204RbKzrW26SYIhjGFdYfFI=; h=Date:To:From:Subject:From; b=NRn4dPTdM+t/fCNI8J93ebhSahpJ+GsXSf4gv85EddM3o9wKx8piXmQPWrbCKXpjI S6rre6j9OxHZXSJl1PeiQNFrNzzltqBL7WG2cvS+2VEof2ZswGBmhwN9Cj5piQvJUy 8J3oFlZMpUFT+3iIFRojhDGfXeraTqSa8Y8NDP48= Date: Sun, 10 Dec 2023 16:55:31 -0800 To: mm-commits@vger.kernel.org,ira.weiny@intel.com,fabio.maria.de.francesco@linux.intel.com,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] mm-swapfile-replace-kmap_atomic-with-kmap_local_page.patch removed from -mm tree Message-Id: <20231211005531.85D52C433C7@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: mm/swapfile: replace kmap_atomic() with kmap_local_page() has been removed from the -mm tree. Its filename was mm-swapfile-replace-kmap_atomic-with-kmap_local_page.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: "Fabio M. De Francesco" Subject: mm/swapfile: replace kmap_atomic() with kmap_local_page() Date: Mon, 27 Nov 2023 16:54:37 +0100 kmap_atomic() has been deprecated in favor of kmap_local_page(). Therefore, replace kmap_atomic() with kmap_local_page() in swapfile.c. kmap_atomic() is implemented like a kmap_local_page() which also disables page-faults and preemption (the latter only in !PREEMPT_RT kernels). The kernel virtual addresses returned by these two API are only valid in the context of the callers (i.e., they cannot be handed to other threads). With kmap_local_page() the mappings are per thread and CPU local like in kmap_atomic(); however, they can handle page-faults and can be called from any context (including interrupts). The tasks that call kmap_local_page() can be preempted and, when they are scheduled to run again, the kernel virtual addresses are restored and are still valid. In mm/swapfile.c, the blocks of code between the mappings and un-mappings do not depend on the above-mentioned side effects of kmap_atomic(), so that the mere replacements of the old API with the new one is all that is required (i.e., there is no need to explicitly call pagefault_disable() and/or preempt_disable()). Link: https://lkml.kernel.org/r/20231127155452.586387-1-fabio.maria.de.francesco@linux.intel.com Signed-off-by: Fabio M. De Francesco Cc: Ira Weiny Signed-off-by: Andrew Morton --- mm/swapfile.c | 34 +++++++++++++++++----------------- 1 file changed, 17 insertions(+), 17 deletions(-) --- a/mm/swapfile.c~mm-swapfile-replace-kmap_atomic-with-kmap_local_page +++ a/mm/swapfile.c @@ -1495,9 +1495,9 @@ int swp_swapcount(swp_entry_t entry) do { page = list_next_entry(page, lru); - map = kmap_atomic(page); + map = kmap_local_page(page); tmp_count = map[offset]; - kunmap_atomic(map); + kunmap_local(map); count += (tmp_count & ~COUNT_CONTINUED) * n; n *= (SWAP_CONT_MAX + 1); @@ -3477,9 +3477,9 @@ int add_swap_count_continuation(swp_entr if (!(count & COUNT_CONTINUED)) goto out_unlock_cont; - map = kmap_atomic(list_page) + offset; + map = kmap_local_page(list_page) + offset; count = *map; - kunmap_atomic(map); + kunmap_local(map); /* * If this continuation count now has some space in it, @@ -3529,7 +3529,7 @@ static bool swap_count_continued(struct spin_lock(&si->cont_lock); offset &= ~PAGE_MASK; page = list_next_entry(head, lru); - map = kmap_atomic(page) + offset; + map = kmap_local_page(page) + offset; if (count == SWAP_MAP_MAX) /* initial increment from swap_map */ goto init_map; /* jump over SWAP_CONT_MAX checks */ @@ -3539,27 +3539,27 @@ static bool swap_count_continued(struct * Think of how you add 1 to 999 */ while (*map == (SWAP_CONT_MAX | COUNT_CONTINUED)) { - kunmap_atomic(map); + kunmap_local(map); page = list_next_entry(page, lru); BUG_ON(page == head); - map = kmap_atomic(page) + offset; + map = kmap_local_page(page) + offset; } if (*map == SWAP_CONT_MAX) { - kunmap_atomic(map); + kunmap_local(map); page = list_next_entry(page, lru); if (page == head) { ret = false; /* add count continuation */ goto out; } - map = kmap_atomic(page) + offset; + map = kmap_local_page(page) + offset; init_map: *map = 0; /* we didn't zero the page */ } *map += 1; - kunmap_atomic(map); + kunmap_local(map); while ((page = list_prev_entry(page, lru)) != head) { - map = kmap_atomic(page) + offset; + map = kmap_local_page(page) + offset; *map = COUNT_CONTINUED; - kunmap_atomic(map); + kunmap_local(map); } ret = true; /* incremented */ @@ -3569,21 +3569,21 @@ init_map: *map = 0; /* we didn't zero */ BUG_ON(count != COUNT_CONTINUED); while (*map == COUNT_CONTINUED) { - kunmap_atomic(map); + kunmap_local(map); page = list_next_entry(page, lru); BUG_ON(page == head); - map = kmap_atomic(page) + offset; + map = kmap_local_page(page) + offset; } BUG_ON(*map == 0); *map -= 1; if (*map == 0) count = 0; - kunmap_atomic(map); + kunmap_local(map); while ((page = list_prev_entry(page, lru)) != head) { - map = kmap_atomic(page) + offset; + map = kmap_local_page(page) + offset; *map = SWAP_CONT_MAX | count; count = COUNT_CONTINUED; - kunmap_atomic(map); + kunmap_local(map); } ret = count == COUNT_CONTINUED; } _ Patches currently in -mm which might be from fabio.maria.de.francesco@linux.intel.com are