Re: [PATCH v4 4/5] cramfs: add mmap support
Richard Weinberger <[email protected]>
| Newsgroups | org.kernel.vger.linux-embedded,org.kernel.vger.linux-fsdevel,org.kernel.vger.linux-kernel,org.kvack.linux-mm |
|---|---|
| Message-ID | <CAFLxGvzfQrvU-8w7F26mez6fCQD+iS_qRJpLSU+2DniEGouEfA@mail.gmail.com> |
On Mon, Oct 2, 2017 at 12:29 AM, Nicolas Pitre <[email protected]> wrote: > On Sun, 1 Oct 2017, Christoph Hellwig wrote: > >> up_read(&mm->mmap_sem) in the fault path is a still a complete >> no-go, >> >> NAK > > Care to elaborate? > > What about mm/filemap.c:__lock_page_or_retry() then? As soon you up_read() in the page fault path other tasks will race with you before you're able to grab the write lock. HTH -- Thanks, //richard -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to [email protected]. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"[email protected]"> [email protected] </a>