2ef7dbb269
When we have locked more than one folios, we cannot wait the lock or bit (e.g., page lock, buffer head lock, writeback bit) synchronously. Otherwise deadlock may be triggered. This make it hard to batch the synchronous migration directly. This patch re-enables batching synchronous migration via trying to migrate in batch asynchronously firstly. And any folios that are failed to be migrated asynchronously will be migrated synchronously one by one. Test shows that this can restore the TLB flushing batching performance for synchronous migration effectively. Link: https://lkml.kernel.org/r/20230303030155.160983-4-ying.huang@intel.com Fixes: 5dfab109d519 ("migrate_pages: batch _unmap and _move") Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Tested-by: Hugh Dickins <hughd@google.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: "Xu, Pengfei" <pengfei.xu@intel.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Stefan Roesch <shr@devkernel.io> Cc: Tejun Heo <tj@kernel.org> Cc: Xin Hao <xhao@linux.alibaba.com> Cc: Zi Yan <ziy@nvidia.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.